Syn isomers of cephalosporins having α-hydroximino- or α-acyloxyiminoacylamido groups at position-7

ABSTRACT

The invention provides novel antibiotic compounds which are 7β-acylamidoceph-3-em-4-carboxylic acids, and non-toxic derivatives thereof, and 6β-acylamidopenam-3-carboxylic acids, and non-toxic derivatives thereof, characterized in that the acylamido group has the structure ##STR1## where R is a hydrogen atom or an organic group and R a  is a hydrogen atom or an acyl group. The compounds are syn isomers or exist as mixtures containing at least 75% of the syn isomer. These antibiotic compounds possess high antibacterial activity against a range of gram positive and gram negative organisms coupled with particularly high stability to β-lactamases produced by various gram negative organisms. The invention is also concerned with the administration of the compounds.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of application Ser. No. 771,807 filedon Feb. 24, 1977, now abandoned, which, in turn, is a division ofapplication Ser. No. 554,014, filed Feb. 28, 1975, and now U.S. Pat. No.4,024,134, which is, in turn, a continuation of application Ser. No.274,602, filed July 24, 1972, and now abandoned, which is, in turn, acontinuation-in-part of application Ser. No. 221,057, filed Jan. 26,1972, and now abandoned.

This invention is concerned with improvements in or relating toantibiotics of the cephalosporin and penicillin series.

As is well known, antibiotics of the cephalosporin and penicillin seriesare respectively 7β-acylamidoceph-3-em-4-carboxylic acids and6β-acylamidopenam-3-carboxylic acids and their various non-toxicderivatives, e.g. salts, esters, lactones (if such can be formed),amides, hydrates or the corresponding sulphoxides. In the cephalosporinseries, these antibiotics may contain various substituents at the3-position including unsubstituted methyl and methyl groups substitutedwith a variety of substituents as is described in the literature. In thepenicillin series, substitution may, for example, be present on at leastone of the gem-dimethyl groups.

The new compounds of the present invention are characterized in thatsaid acylamido group of the cephalosporin or penicillin antibiotic is anα-hydroxyiminoacylamido or α-acyloxyiminoacylamido group, the compoundsbeing syn isomers or mixtures wherein the syn isomeric formpredominates.

According to one embodiment of the invention, therefore, we provide acompound selected from the group of 7β-acylamidoceph-3-em-4-carboxylicacids (and non-toxic derivatives thereof) and6β-acylamidopenam-3-carboxylic acids (and non-toxic derivatives thereof)characterized in that said acylamido group has the structure: ##STR2##where R is a hydrogen atom or an organic group and R^(a) is a hydrogenatom or an acyl group, said compound being a syn isomer or existing as amixture containing at least 75% of the syn isomer.

The compounds of the invention are defined as having the syn (cis)isomeric form as regards the configuration of the group OR^(a) withrespect to the carboxamido group. Preferably, the mixtures of isomerscontain at least 90% of the syn isomer and not more than 10% of theanti.

In this specification, the syn configuration is structurally denotedthus: ##STR3## and the anti configuration thus: ##STR4##

These configurations are allocated on the work of Ahmad and Spencer,Can. J. Chem, 1961, 39, 1340.

The compounds of the invention may be defined by the formula: ##STR5##where R^(a) has the above-defined meaning, R is a hydrogen atom or anorganic group B is >S or >S→O and Z is a group in which 1 or 2 carbonatoms link the nuclear sulphur atom and the carbon atom bearing thecarboxyl group.

The term "non-toxic" as applied to the derivatives of the compounds ofthe invention means those derivatives which are physiologicallyacceptable in the dosage at which they are administered.

Salts which may be formed, where applicable, from the compoundsaccording to the invention include (a) inorganic base salts such asalkali metal, e.g. sodium and potassium, alkaline earth metal e.g.calcium, and organic base, e.g. procaine, phenylethylbenzylamine anddibenzylethylene diamine, salts and (b) acid addition salts e.g., withhydrochloric, hydrobromic, sulphuric, nitric, phosphoric,toluene-p-sulphonic and methane sulphonic acids. The salts may also bein the form of resinates, formed e.g., with a polystyrene resincontaining amino, quaternary amino, or sulphonic acid groups, or a resincontaining carboxyl groups, e.g. a polyacrylic acid resin. The resin mayif desired be cross-linked, e.g. it may be a copolymer of styrene anddivinyl-benzene containing the appropriate groups. Additionally, thederivatives may be in the form of a chelate with a heavy metal such asiron or copper.

The compounds of the invention, including the non-toxic derivativesthereof, are characterized by their high antibacterial activity againsta range of gram-positive and gram-negative organisms coupled withparticularly high stability to β-lactamases produced by various gramnegative organisms.

Stability to β-lactamases may be assessed as compared with cephaloridinewhich may be arbitrarily defined as having a value of 1 with respect tothe particular organism.

The cephalosporin compounds referred to in this specification aregenerally named with reference to cepham (J. Amer. Chem. Soc. 1962, 843400). The term "cephem" refers to the basic cepham structure with onedouble bond. The penicillin compounds referred to in this specificationare generally named with reference to penam (J. Amer. Chem. Soc. 1953,75, 3293).

The cephalosporin compounds according to the invention may be defined ascompounds of the general formula ##STR6## (wherein R, R^(a) and B havethe above defined meanings, P is an organic group) and non-toxicderivatives thereof.

The penicillin compounds according to the invention may be defined ascompounds of the general formula ##STR7## (wherein R, R^(a) and B havethe above-defined meanings) and non-toxic derivatives thereof.

In formulae (II) and (III) B is preferably >S.

The invention also includes cephalosporin and penicillin compounds notspecifically embraced by formulae (II) or (III) e.g. 2β-acetoxymethylpenicillins and 2-methyl and 2-methylene cephalosporins.

The group R^(a) in the above formulae, when it is acyl, may be chosenfrom a wide variety of possible groups. Thus the group R^(a) may be acarboxylic acyl group R^(c) CO having from 1 to 20 carbon atoms. Inparticular R^(c) may be an aliphatic, cycloaliphatic or aromatic groupor it may be such an organic group linked to the carbonyl group throughan oxygen atom, a sulphur atom or an imino group. Such an aliphatic,cycloaliphatic or aromatic group may be substituted by halogen (F, Cl,Br or I), amino, nitro, C₁ -C₅ alkyl, C₁ -C₆ alkoxy etc.

Particular Examples of R^(a) include alkanoyl, alkenoyl and alkynoyl ofup to 7 carbon atoms e.g. acetyl, propionyl, butyryl, acrylyl, crotonyl;substituted, e.g. halogenated (F, Cl, Br, I) or amino or substitutedamino derivatives of such groups e.g. chloroacetyl, dichloroacetyl orβ-aminopropionyl; alkoxycarbonyl of up to 7 carbon atoms e.g.ethoxycarbonyl, and t-butoxycarbonyl; substituted alkoxycarbonyl e.g.2,2,2-trichloroethoxycarbonyl; alkylthiocarbonyl of up to 7 carbon atomsand substituted derivatives thereof; aralkyloxycarbonyl e.g.benzhydryloxycarbonyl and benzyloxycarbonyl; C₇ -C₁₃ aroyl e.g. benzoyland substituted, e.g. nitrated derivatives of such groups e.g.nitrobenzoyl; and substituted or unsubstituted carbamoyl orthiocarbamoyl i.e. compounds in which the group R^(a) has the formula(R^(b))₂ N.CO-- or (R^(b))₂ N.CS-- and R^(b) is the same or differentand each is a hydrogen atom or a substituent such as alkyl of 1-7 carbonatoms e.g. ethyl or methyl and substituted, e.g. halogenated, alkyl of1-7 carbon atoms e.g. chloroethyl, or R^(u), where R^(u) has the meaningdefined below.

The group R in the above general formulae may be chosen from thefollowing list which is not intended to be exhaustive:

(i) Hydrogen,

(ii) R^(u), where R^(u) is aryl (carbocyclic or heterocyclic),cycloalkyl, substituted aryl, substituted cycloalkyl, cycloalkadienyl,or a non-aromatic or mesionic group. Examples of this group includephenyl; naphthyl; phenyl or naphthyl substituted by halo e.g. chloro orbromo, hydroxy, lower alkyl e.g. methyl, nitro, amino, lower alkylaminoe.g. methylamino, diloweralkylamino e.g. dimethylamino, lower alkanoyle.g. acetyl, lower alkanoylamido, lower alkoxy e.g. methoxy or ethoxy,or lower alkylthio e.g. methylthio; a 5- or 6-membered heterocyclicgroup containing at least one hetero atom selected from S, N and O e.g.thien-2-yl, thien-3-yl, furyl, pyridyl, 3- or 4-isoxazolyl; substituted3- or 4-isoxazolyl e.g. 3-aryl-5-methylisoxazol-4-yl, the aryl groupbeing e.g. phenyl or halophenyl; cyclohexyl; cyclopentyl; sydnone; andcyclohexadienyl.

(iii) R^(u) (CH₂)_(m) Q_(n) (CH₂)_(p) where R^(u) has the above definedmeaning and m is 0 or an integer from 1 to 4, n is 0 or 1, p is aninteger from 1 to 4 and Q is S, O or NR wherein R is hydrogen or anorganic group e.g. alkyl such as methyl or aryl such as phenyl. Examplesof this group include methyl, ethyl or butyl substituted by the variousspecific R^(u) groups listed under (ii) e.g. benzyl and the appropriatesubstituted benzyl groups.

(iv) C_(n) H_(2n+1) wherein n is an integer from 1 to 7. The group maybe straight or branched and, if desired, may be interrupted by an oxygenor sulphur atom or the group NR wherein R is hydrogen or an organicgroup e.g. alkyl such as methyl or aryl such as phenyl; or besubstituted by a cyano, carboxy, alkoxycarbonyl, hydroxy orcarboxycarbonyl (HOOC.CO.) group or by a halogen atom. Examples of suchgroups include hexyl, heptyl, butylthiomethyl, cyanomethyl ortrihalomethyl.

(v) C_(n) H_(2n-1) where n is an integer from 2 to 7. The group may bestraight or branched and, if desired, may be interrupted by an oxygen orsulphur atom or the group NR wherein R is hydrogen or an organic groupe.g. alkyl such as methyl or aryl such as phenyl. An example of such agroup is vinyl or propenyl.

(vi) C_(n) H_(2n-3) where n is an integer from 2 to 7. An example ofsuch a group is ethynyl.

(vii) Miscellaneous carbon-linked organic groups including cyano, amidoand lower alkoxycarbonyl.

The 3-substituent P of the above cephalosporin compounds may be anyorganic group, the characterising feature of the invention being thenature of the 7-substituent. P may thus be a saturated or unsaturated,substituted or unsubstituted, organic group containing 1-20 carbonatoms. Preferred saturated organic groups include methyl and ethyl;preferred unsaturated organic groups include vinyl and substituted vinylgroups of the formula ##STR8## wherein R³ and R⁴, which may be the sameor different, are each hydrogen or a substituted or unsubstitutedaliphatic (e.g. alkyl, preferably C₁ -C₆ alkyl such as methyl, ethyl,iso-propyl, n-propyl etc.), C₅ -C₇ cycloaliphatic (e.g. cyclopentyl orcyclohexyl), C₇ -C₁₀ araliphatic (e.g. benzyl or phenvlethyl), C₆ -C₁₂aromatic (e.g. phenyl or nitrophenyl) group, nitrile or loweralkoxycarbonyl.

When P is a substituted methyl group it may be depicted by the formula

    --CH.sub.2 Y

wherein Y is an atom or group e.g. the residue of a nucleophile or aderivative of a residue of a nucleophile. Y may thus, for example, bederived from the wide range of nucleophilic substances characterized bypossessing a nucleophilic nitrogen, carbon, sulphur or oxygen atomdescribed widely in earlier patents and literature pertaining tocephalosporin chemistry. Examples of such nucleophiles include:

NITROGEN NUCLEOPHILES

Examples of nitrogen nucleophiles include tertiary aliphatic, aromatic,araliphatic and cyclic amines including trialkylamines, for example,triethylamine, pyridine bases such as pyridine and alkyl pyridines;heterocyclic amines having more than one heteroatom, at least oneheteroatom being nitrogen, such as pyrimidines, purines, pyridazines,pyrazines, pyrazoles, imidazoles, triazoles and thiazoles.

A preferred class of nitrogen nucleophile are those compounds of theformula: ##STR9## in which n is 0 or an integer from 1 to 5 and R^(d),which when n is from 2 to 5, may be the same or different, is analiphatic, e.g. lower alkyl such as methyl, ethyl, n-propyl, iso-propyletc; an aryl e.g. phenyl; an araliphatic, e.g. phenyl lower alkyl suchas benzyl, phenylethyl etc; or an alkoxymethyl e.g. methoxymethyl,ethoxymethyl, n-propoxymethyl, iso-propoxymethyl etc; or acyloxymethyle.g. alkanoyloxymethyl such as acetoxymethyl; formyl; carbamoyl; acyloxye.g. alkanoyloxy such as acetoxy; esterified carboxyl; alkoxy e.g.methoxy, ethoxy, n-propoxy, iso-propoxy etc; aryloxy e.g. phenoxy;aralkoxy e.g. benzyloxy; alkylthio e.g. methylthio, ethylthio; arylthio;aralkylthio; cyano; hydroxy; N-monoloweralkylcarbamoyl e.g.N-methylcarbamoyl, N-ethylcarbamoyl etc; N,N-diloweralkylcarbamoyl e.g.N,N-dimethylcarbamoyl, N,N-diethylcarbamoyl etc;N-(hydroxyloweralkyl)carbamoyl e.g. N-(hydroxymethyl)carbamoyl,N-(hydroxyethyl)carbamoyl etc; or carbamoylloweralkyl e.g.carbamoylmethyl, carbamoylethyl etc. group.

Another preferred class of nitrogen nucleophiles are azides e.g. alkalimetal azides such as sodium azide.

When the group Y is a derivative of a residue of a nucleophile it may bean amino group or an acylamido group. Compounds in which Y is amino maybe derived from the corresponding azide by reduction e.g. by catalytichydrogenation of the azide using a precious metal catalyst such aspalladium or platinum.

The amino group may be acylated to form a corresponding3-acylaminomethyl compound. The formation of such compounds may, forexample, be effected by any method suitable for acylating anaminocephalosporin e.g. reaction of the 3-aminomethyl compound with anacid chloride, acid anhydride or mixed anhydride or an acidcorresponding to the desired acyl group and another acid.

The 3-aminomethyl compounds may also be reacted with a substitutedisocyanate or isothiocyanate to yield urea or thiourea derivatives.

Other compounds in which Y is a derivative of a residue of a nucleophilemay be obtained by reacting 3-azidomethyl compounds with adipolarophile. Preferred classes of dipolarophiles include acetylenic,ethylenic and cyano dipolarophiles.

Acetylenic dipolarophiles may be shown as having the structure

    R.sup.1.C.tbd.C.R.sup.2

where R¹ and R² which may be the same or different are atoms or groups.

In general we prefer that R¹ and preferably also R² should be of anelectronegative nature. Examples of such groups include cyano, CO₂ R³,COR³ (where R³ is for example, lower alkyl, aryl or lower aralkyl), andtrihalomethyl e.g. trifluoromethyl.

However, R¹ and preferably also R² could be electropositive e.g. alkoxyor alkylamino.

R¹ and R² may together form a ring system with the acetylenic group suchas, for example, in an aryne.

Where R¹ and R² are discrete atoms or groups which are identical asingle compound will result on reaction with the azido cephalosporin; ifthey are different one will in general obtain a mixture of positionisomers.

Ethylenic dipolarophiles may be shown as having the structure ##STR10##where R⁵, R⁶, R⁷ and R⁸ which may be the same or different are atoms orgroups. Although R⁵, R⁶, R⁷ and R⁸ may all be hydrogen, ethylene per se,like acetylene, reacts sluggishly with azido groups. R⁵ and R⁷ maytogether form a cyclic structure, e.g. a carbocyclic structure, with theethenoid group such that the double bond is strained. Examples ofethylenic dipolarophiles containing strained double bonds includenorbornenes, transcycloalkenes and acenaphthalene.

Further ethylenic dipolarophiles which may be used include compounds ofthe formula R⁵.R⁶.C═CR⁷.R⁸ where at least one of R⁵, R⁶, R⁷ and R⁸ is anelectronegative group. R⁵ and R⁷ may thus be identical electronegativegroups, R⁶ and R⁸ being other groups as desired. R⁶ and R⁸ may thustogether form a ring system. Examples of such dipolarophiles includebenzoquinone and nuclear substituted benzoquinones and maleimide. Againall of R⁵, R⁶, R⁷ and R⁸ may be identical electronegative groups.Electronegative groups which may be used include those listed under thesection on acetylenic dipolarphiles and examples of such compounds thusinclude dicyanoethylene and lower mono- and di-alkoxycarbonyl ethylenes.

One or more of R⁵, R⁶, R⁷ and R⁸ may if desired be electropositive.

Cyano compounds, especially those which are activated by electronegativegroups, may function as cyano dipolarophiles. Examples of suchdipolarophiles include lower alkoxy carbonyl cyanides and cyanogen.

CARBON NUCLEOPHILES

Examples of "carbon nucleophiles" include inorganic cyanides, pyrrolesand substituted pyrroles, e.g. indoles, and compounds giving stabilisedcarbanions, for example, acetylenes and compounds having β-diketonegroups, for example acetoacetic and malonic esters andcyclohexane-1,3-diones or enamines, ynamines or enols.

The carbon nucleophile may thus give rise to cephalosporin compoundscharacterized by possessing a substituent at the 3-position in which acarbonyl group is linked to the cephalosporin nucleus through two carbonatoms. Such compounds may thus possess as the 3-substituent a group ofthe formula ##STR11## wherein R² and R³, which may be the same ordifferent, are selected from hydrogen, cyano, lower alkyl e.g. methyl orethyl, phenyl, substituted phenyl e.g. halo, lower alkyl, lower alkoxy,nitro, amino or lower alkylamino phenyl, lower alkoxycarbonyl, mono- ordi-aryl lower alkoxycarbonyl, lower alkylcarbonyl, aryl lower alkyl orC₅ or C₆ cycloalkyl and R⁴ is selected from hydrogen, lower alkyl e.g.methyl or ethyl, phenyl, substituted phenyl e.g. halo, lower alkyl,lower alkoxy, nitro, amino or lower alkylamino phenyl, aryl lower alkylor C₅ or C₆ cycloalkyl.

SULPHUR NUCLEOPHILES

Examples of "sulphur nucleophiles" include thiourea and aliphatic,aromatic, araliphatic, alicyclic and heterocyclic substituted thioureas;dithiocarbamates; aromatic, aliphatic and cyclic thioamides, for examplethioacetamide and thiosemicarbazide; thiosulphates; thiols; thiophenols;thioacids, e.g. thiobenzoic acid or thiopicolinic acid; and dithioacids.

A preferred class of "sulphur nucleophile" includes those compounds ofthe formula: R¹.S(O)_(n) H in which R¹ is an aliphatic e.g. lower alkylsuch as methyl, ethyl, n-propyl etc. group; an alicyclic e.g.cyclohexyl, cyclopentyl etc. group; an aromatic e.g. phenyl, naphthyletc. group; an araliphatic e.g. benzyl group; or a heterocyclic group,and n is 0, 1 or 2. A particularly preferred class of nucleophilesfalling within the above formula is that having the general formula: R⁶SH in which R⁶ is an aliphatic, e.g. lower alkyl e.g. methyl ethyl,n-propyl etc.; araliphatic, e.g. phenyl lower alkyl e.g. benzyl,phenylethyl etc. or substituted phenyl lower alkyl; alicyclic e.g.cycloalkyl e.g. cyclopentyl or cyclohexyl; aromatic e.g. phenyl orsubstituted phenyl or a 5- or 6-membered heterocyclic group containingat least one of O, N and S e.g. thiadiazolyl particularly5-methyl-1,3,4-thiadiazol-2-yl, diazolyl, triazolyl, tetrazolyl,thiazolyl, thiatriazolyl, oxazolyl, oxadiazolyl, benzimidazolyl,benzoxazolyl, triazolopyridyl, purinyl pyridyl, pyrimidyl, etc.

OXYGEN NUCLEOPHILES

Examples of oxygen nucleophiles include water, alcohols, for examplealkanols such as methanol, ethanol, propanol and butanol and loweralkanoic acids.

The term "oxygen nucleophile" thus includes compounds of the followingformula:

    R.sup.t OH

in which the group R^(t) may be lower alkyl (e.g. methyl, ethyl,n-propyl, isopropyl, n-butyl, isobutyl etc.); lower alkenyl (e.g.alkyl); lower alkynyl (e.g. propynyl, etc); lower cycloalkyl (e.g.cyclopentyl, cyclohexyl, etc); lower cycloalkyl lower alkyl (e.g.cyclopentylmethyl, cyclohexylethyl etc); aryl (e.g. phenyl or naphthyl);aryl lower alkyl (e.g. benzyl); heterocyclic; heterocyclic lower alkyl(e.g. furfuryl) or any of these groups substituted by, for example, oneor more of lower alkoxy (methoxy, ethoxy, etc.), lower alkylthio(methylthio, ethylthio, etc), halogen (chlorine, bromine, iodine orfluorine), lower alkyl (methyl, ethyl etc), nitro, hydroxy, acyloxy,carboxy, carbalkoxy, lower alkylcarbonyl, lower alkylsulphonyl, loweralkoxysulphonyl, amino, lower alkylamino or acylamino groups.

In the case in which is the nucleophile there will be obtained3-hydroxymethyl cephalosporin compounds. Such compounds have the formula##STR12## where R and R^(a) have the above defined meanings. Compoundsof formula (A) and non-toxic derivatives thereof possess antibacterialactivity and it is of note that they may be metabolites of compounds ofgeneral formula (IV) where P is acyloxymethyl. Compounds of formula (A)may be acylated to form derivatives characterised by possessing thegroup 3--CH₂.O.CO.R⁹ or 3--CH₂.O.CO.ZR⁹ where Z is 0 or 5 in which R⁹ ismethyl or an organic group having an atomic weight sum of at least 16.

The group R⁹ CO-- or, R⁹ Z.CO-- may be chosen from among the wide classof such groups described to the literature and may have up to 20 carbonatoms. The group R⁹ may thus be a hydrocarbon group or such a groupcarrying one or more substituent atoms or groups. The group R⁹ may thusbe chosen from the following list which is not intended to beexhaustive:

(i) C_(n) H_(2n+1) where n is an integer from 1 to 7, e.g. 2 to 4. Thegroup may be straight or branched and, if desired, may be interrupted byan oxygen or sulphur atom or an imino group or substituted by cyano,carboxy, alkoxycarbonyl, hydroxy, carboxycarbonyl (HOOC.CO.), halogene.g. chlorine, bromine or iodine, or amino. Examples of such groupsinclude ethyl, propyl, isopropyl, n-butyl, t-butyl or sec.butyl

(ii) C_(n) H_(2n-1) where n is an integer from 2 to 7. The group may bestraight or branched and, if desired, may be interrupted by an oxygen orsulphur atom or an imino group. An example of such a group is vinyl orpropenyl.

(iii) R^(v), where R^(v) is aryl (carbocyclic or heterocyclic),cycloalkyl, substituted aryl and substituted cycloalkyl. Examples ofthis group include phenyl; substituted phenyl e.g. hydroxyphenyl,chlorophenyl, fluorophenyl, tolyl, nitrophenyl, aminophenyl,methoxyphenyl or methylthiophenyl; thien-2- and -3-yl; pyridyl;cyclohexyl; cyclopentyl; sydnone; naphthyl; substituted naphthyl e.g.2-ethoxynaphthyl.

(iv) R^(v) (CH₂)_(m) where R^(v) has the meaning defined above under(iii) and m is an integer from 1 to 4. Examples of this group includemethyl, ethyl or butyl substituted by the various specific R^(v) groupslisted under (iii) e.g. benzyl and the appropriate substituted benzylgroups.

Compounds of formula (A) may also be acylated to form derivativescharacterised by possessing the group 3--CH₂.O.CO.NH(CH₂)_(m) R, where Ris hydrogen or halogen (Cl, Br, I or F) and m is an integer from 1-4.

An important class of cephalosporin compounds are those possessing thegroup 3--CH₂ Hal wherein Hal is chlorine, bromine or iodine. Suchcompounds may be primarily of value as intermediates of use in thepreparation of active cephalosporin compounds.

Important antibiotic compounds according to the invention by virtue oftheir broad spectrum antibiotic properties coupled with stability ofβ-lactamase produced by a variety of organisms are compounds of thegeneral formulae ##STR13## and non-toxic derivatives thereof. Informulae (B) (C) and (D) R^(u) is phenyl; naphthyl; thienyl; furyl;pyridyl; phenyl, naphthyl, thienyl, furyl or pyridyl substituted byhalo, hydroxy, lower alkyl, nitro, amino, loweralkylamino,diloweralkylamino, lower alkanoyl, lower alkanoylamino, lower alkoxy,lower alkythio or carbamoyl; R⁹ is C₂ -C₄ alkyl or C₂ -C₄ alkenyl; and Ris C₁ -C₄ alkyl, C₁ -C₄ chloroalkyl, C₁ -C₄ alkoxy, phenyl, nitrophenylor C₁ -C₄ chloroalkylamino.

Other important antibiotic compounds according to the invention arethose of the general formula ##STR14## (wherein R^(u) is as definedunder (B), (C) and (D) and W is thiadiazolyl, preferably5-methyl-1,3,4-thiadiazol-2-yl, diazolyl, triazolyl, tetrazolyl,preferably 1-methyltetrazol-5-yl, thiazolyl, thiatriazolyl, oxazolyl,oxadiazolyl, benzimidazolyl, benzoxazolyl, triazolopyridyl, purinyl,pyridyl or pyrimidyl) and non-toxic derivatives thereof.

Compounds of formula (E) possess a very high degree of activity againsta variety of gram positive and gram negative organisms coupled with highstability to β-lactamases produced by a variety of organisms. A furthersignificant property of these compounds is their stability to mammalianesterases.

Other important antibiotic compounds according to the invention arethose having the general formula ##STR15## (wherein R^(u) is as definedabove under (B), (C) and (D) and R⁶ is C₁ -C₄ alkyl) and non-toxicderivatives thereof. These compounds are broad spectrum antibioticspossessing properties of oral absorption. They also have stability toβ-lactamases produced by a variety of organisms.

A particularly preferred class of cephalosporin antibiotic compoundsaccording to the invention are those of the formula ##STR16## (whereinR¹⁰ is phenyl, thien-2-yl or fur-2-yl, R^(a) has the above-definedmeaning and is preferably hydrogen and R" is acetoxy, crotonyloxy,isobutyryloxy, methoxy, 5-methyl-1,3,4-thiadiazol-2-ylthio or1-methyltetrazol-5-yl thio) and base salts thereof e.g. sodium orpotassium salts. Important compounds falling within this class includethe following compounds in their syn isomeric form

3-acetoxymethyl-7β-(2-hydroxyimino-2-phenylacetamido)ceph-3-em-4-carboxylicacid;

3-acetoxymethyl-7β-[2-hydroxyimino-2-(thien-2-yl)acetamido]ceph-3-em-4-carboxylic acid;

7β-[2-hydroxyimino-2-(thien-2-yl)acetamido]-3-(5-methyl-1,3,4-thiadiazol-2-ylthiomethyl)ceph-3-em-4-carboxylicacid;

7β-(2-hydroxyimino-2-phenylacetamido)-3-(5-methyl-1,3,4-thiadiazol-2-ylthiomethyl)ceph-3-em-4-carboxylicacid;

7β-[2-hydroxyimino-2-(thien-2-yl)-acetamido]-3-(1-methyltetrazol-5-ylthiomethyl)-ceph-3-em-4-carboxylicacid (syn-isomer);

7β-[2-hydroxyimino-2-(fur-2-yl)acetamido]-3-(1-methyltetrazol-5-ylthiomethyl)-ceph-3-em-4-carboxylicacid;

especially as their sodium or potassium salts.

These six last-mentioned compounds are broad spectrum antibiotics, beingactive against a wide variety of gram-positive, (penicillin-resistantand penicillin sensitive strains of Staph. aureus) and gram-negativeorganisms as evidence by in vitro and in vivo tests. Moreover, thecompounds are markedly resistant to β-lactamases produced by a varietyof gram positive and gram negative organisms.

Preparation

The compounds according to the invention may be prepared by anyconvenient method. According to one embodiment of the invention weprovide a process for the preparation of a compound of the formula##STR17## (wherein R is a hydrogen atom or an organic group, R^(a) ishydrogen or an acyl group, B is>S or>S→O and Z is a group in which 1 or2 carbon atoms link the nuclear sulphur atom and the carbon atom bearingthe carboxyl group) and derivatives thereof, which comprises either (A)condensing a compound of the formula ##STR18## (wherein B and Z have theabove defined meanings and R¹ is hydrogen or a carboxyl blocking group)with an acylating agent, advantageously the syn isomer, corresponding tothe acid ##STR19## (wherein R and R^(a) have the above defined meanings)or with an acylating agent corresponding to an acid which is a precursorfor the acid (VI) and converting the resulting precursor acyl group intothe desired acyl group; or (B) reacting a compound of the formula##STR20## (wherein B, Z and R¹ have the above defined meaning exceptthat R¹ is not hydrogen) with an acid of formula (VI) wherein R^(a) isnot hydrogen; or (C), where Z is the group ##STR21## (wherein Y is theresidue of a nucleophile or a derivative of the residue of a nucleophileand the dotted line bridging the 2,3 and 4 positions indicates that thecompound may be a ceph-2-em or a ceph-3-em compound) reacting a compoundof the formula ##STR22## (wherein Acyl is the group ##STR23## or aprecursor therefor; B, R^(a), R¹ and the dotted line have the abovemeanings and Y¹ is a replaceable residue of a nucleophile) with anucleophile whereafter, if necessary and desired in each instance, anyof the following reactions (D) are carried out (i) conversion of aprecursor for the desired ##STR24## group into that said group (ii)conversion of a Δ² isomer into the desired Δ³ isomer (iii) removal ofany carboxyl blocking groups (iv) reduction of a compound in which Zis>S→O to form the desired Z=>S compound (v) reduction of a compound inwhich Y is azide to form a 3-aminomethyl compound (vi) reaction of acompound in which Y is azide with a depolarophile to form a compoundhaving a polyazole ring linked to the 3-methylene group (vii)deacylation of a compound in which Y is an acyloxy group to form a3-hydroxymethyl compound and (viii) acylation of a compound in which Yis hydroxy to form a 3-acyloxymethyl compound and, (E) recovering thedesired compound of formula (I), if necessary, after separation ofisomers.

Salts of the compounds according to the invention may be formed in anyconvenient way. For example base salts may be formed by reaction of thepenicillin or cephalosporin acid with sodium or potassium2-ethylhexanoate.

In practice it is convenient to condense an acylating agentcorresponding to the acid ##STR25## where R and R^(a) have the abovedefined meanings, with an amino compound ##STR26## [where Z and B havethe above defined meanings and R¹ is hydrogen or a carboxyl blockinggroup e.g. the residue of an ester-forming alcohol (aliphatic oraraliphatic), phenol, silano), stannoanol or acid] the condensation, ifdesired, being effected in the presence of a condensation agent, andbeing followed, if necessary, by removal of the group R¹.

In the case of the preparation of cephalosporin and penicillin compoundsthe amino compound (VII) may correspond to compounds (II) and (III)above and have the formulae ##STR27## respectively, wherein R¹, B and Phave the above defined meanings. There may also be used a derivative ofthe amino compounds such as a salt e.g. a tosylate.

Compounds in which R^(a) is hydrogen may be prepared indirectly andcompounds in which R^(a) is not hydrogen may be prepared directly byemploying as the acylating agent an acid halide, particularly an acidchloride or bromide. In the preparation of a compound in which R^(a) ishydrogen by this technique an additional step will be necessary in whichthe acyl group R^(a) is removed to yield the hydroximino compound. Theacylation may be effected at temperatures of from -50° to +50° C.,preferably from -20° to +20° C. e.g. about 0° C. The acylating agent maybe prepared by reacting the acid (VI) in which R^(a) is not hydrogenwith a halogenating agent e.g. phosphorus pentachloride, thionylchloride or oxalyl chloride. The acylation may be effected in aqueous ornon-aqueous media and suitable media include an aqueous ketone such asaqueous acetone, an ester e.g. ethyl acetate, or an amide e.g.dimethylacetamide, or a nitrile e.g. acetonitrile, or mixtures thereof.

Acylation with an acid halide may be effected in the presence of an acidbinding agent e.g. a tertiary amine (e.g. triethylamine ordimethylaniline), an inorganic base (e.g. calcium carbonate or sodiumbicarbonate) or an oxirane, which binds hydrogen halide liberated in theacylation reaction. The oxirane is preferably a lower-1, 2-alkyleneoxide e.g. ethylene oxide or propylene oxide.

When using the free acid form of a compound of formula (VI) and, ifdesired, where R^(a) =H, suitable condensing agents for use in thepreparation of the compounds according to the invention includecarbodiimides, for example N,N'-diethyl-, dipropyl- ordiisopropylcarbodiimide, N,N'-dicyclohexylcarbodiimide, orN-ethyl-N'-γ-dimethylaminopropylcarbodiimide; a suitable carbonylcompound, for example carbonyldiimidazole; or an isoxazolinium salt, forexample, N-ethyl-5-phenylisoxazolinium-3'-sulphonate andN-t-butyl-5-methylisoxazolinium perchlorate. The condensation reactionis desirably effected in an anhydrous reaction medium, e.g. methylenechloride, dimethylformamide or acetonitrile, since one may then regulatemore precisely reaction parameters such as temperature.

Alternatively, acylation may be effected with other amide-formingderivatives of the free acid such as, for example, a symmetricalanhydride or mixed anhydride, e.g. with pivalic acid or formed with ahaloformate, e.g. a lower alkylhaloformate. The mixed or symmetricalanhydrides may be generated in situ. For example, a mixed anhydride maybe generated using N-ethoxycarbonyl-2-ethoxy-1, 2-dihydroquinoline.Mixed anhydrides may also be formed with phosphorus acids (for examplephosphoric or phosphorous acids), sulphuric acid or aliphatic oraromatic sulphonic acids (for example p-toluene sulphonic acid). Anotherconvenient acylating agent is an activated ester e.g. a compound of theformula ##STR28## where W, is for example, azide, oxysuccinimide,oxybenztriazole, pentachlorophenoxy or p-nitrophenoxy group.

One may prepare compounds according to the invention in which R^(a) =Hby condensing an acylating agent corresponding to the acid (VI) in whichR^(a) is not hydrogen but is a group which can be readily removed toyield the desired group ═N˜OH with the amino compound (VIII). The R^(a)group is removed subsequently, if desired inconjunction with the removalof the group R¹. Illustrative of such readily removable R^(a) groups areacetyl, if desired having at least one electron-withdrawing group on theα-carbon atom e.g. trichloroacetyl, dichloroacetyl, monochloroacetyl,trifluoroacetyl, difluoroacetyl and monofluoroacetyl; formyl;benzhydryloxycarboxy, benzyloxycarbonyl, t-butoxycarbonyl and2,2,2-trichloroethoxycarbonyl. The removal of such groups may forexample be effected under mildly basic conditions. Thus, for example, anacetyl group may be removed by means of treatment with aqueous alkali.Halogenated acetyl groups may be removed by means of aqueous bicarbonateand, additionally, chloroacetyl can be removed using a nucleophile suchas a thiourea. Benzhydryloxycarbonyl and t-butoxycarbonyl groups can beremoved using trifluoroacetic acid with or without anisole.2,2,2-Trichloroethoxycarbonyl may be removed by means of a reducingagent such as zinc/acetic acid or zinc/formic acid. It will beappreciated that although the preparation of compounds having readilyremovable R^(a) groups affords a convenient route to hydroxyiminocompounds, compounds with such R^(a) groups are also compounds accordingto the invention and may possess desirable properties in their ownright.

Alternatively the compound of formula (I) may be prepared from acompound of formula ##STR29## where B, Z and R¹ have the above definedmeanings (except R¹ =H) by reaction with an acid of formula (VI) (exceptwhere R^(a) =H) and subsequently removing the groups R¹ and, if desired,R^(a) (see for example Dutch Patent Application No. 6808622 and BelgianPatent No. 760494).

The reaction of the compound of formula (VII) or (XI) may be carried outtowards the end of the preparative sequence, the only additionalreactions being deprotection reactions and purifications.

Compounds of formula I where R^(a) =acyl may be obtained from thecorresponding compounds of formula I where R^(a) =H or from estersthereof (i.e. having at the 4-position a group COOR¹, R¹ having theabove defined meaning) by acylation. Acylation may be effected in anyconvenient manner e.g. using an acid halide, symmetrical or mixedanhydride, ketene, acyl azide or carbodiimide (when the 4-carboxy groupis protected) corresponding to the acid R^(a) OH. Alternatively theacylation may be effected by means of a haloformate for example achloroformate such as ethylchlorformate whereupon one will obtaincarbonates or by means of an isocyanate R⁶ NCO for example 2-chloroethylisocyanate whereupon one will obtain carbonates in which OR^(a) has theformula R^(b) NHCO.O-- where R^(b) has the above defined meaning. Theacylation may be catlysed e.g. by a base such as triethylamine,diethylaniline, pyridine, propylene oxide, magnesium oxide, sodiumcarbonate or calcium carbonate. The acylation may be effected in anorganic solvent. Suitable solvents include halogenated hydrocarbons e.g.methylene chloride; cyclic ethers e.g. dioxan or tetrahydrofuran;nitriles e.g. acetonitrile; nitrohydrocarbons e.g. nitromethane; esterse.g. ethyl acetate; or the acylating agent itself. The acylation may beeffected at a temperature of -10° to +100° C., preferably 0° to 50° C.advantageously 0° to 30° C. After the acylation has been effected thegroup R¹ is removed, if necessary.

If desired, one can first prepare a compound of formula ##STR30## (whereR, R¹, B and Z have the above defined meanings) and then effect reactionof the compound of formula (XII) with R^(a) O.NH₂ (R^(a) having theabove defined meaning), followed, if ncessary by removal of the groupR¹. The reaction product may be separated into syn and anti isomersbefore or after removal of R¹.

One may prepare compounds of formula (I) wherein R is an activatinggroup such as cyano or pyridyl by a technique involving nitrosation.Thus a compound possessing the acylamido group ##STR31## may benitrosated using, for example, nitrous acid (which may be prepared insitu by reaction of an alkali metal nitrite with a weak acid e.g. aceticacid), nitrosyl chloride, or an organic nitrosating agent e.g. an alkyl,cycloalkyl, aryl or aralkyl nitrite. In the case of rnitrosation of acompound containing the group ##STR32## concomitant decarboxylation willoccur. Separation of syn and anti-isomers may be necessary after thenitrosation reaction.

If desired the replacement of one P group by another and preferred Pgroup may be carried out after acylation of the 7-amino compound hastaken place. In particular when P is the group

    --CH.sub.2 Y

where Y has the above defined meaning the Y group may be introduced bymethods described in the literature. Thus compounds in which Y is ahalogen atom, an ether group, or a thioether group may be prepared asdescribed in Belgian Patents Nos. 719,711; 719,710; 734,532 and 734,533.Compounds wherein Y is the residue of a nucleophile may also be preparedby the reaction of a 3-acetoxymethyl cephalosporin compound with anucleophile, for example, pyridine or other tertiary amine as describedin British Patent No. 912,541; a sulphur-linking, nitrogen-linking orinorganic nucleophile as described in British Patent No. 1,012,943; asulphur-linking nucleophile as described in British Patents Nos.1,059,562, 1,101,423 and 1,206,305; or a nitrogen-linking nucleophile asdescribed in British Patents Nos. 1,030,630, 1,082,943 and 1,082,962.

Compounds in which Y is a derivative of a residue of a nucleophile suchas an amino or acylamido group derived from an azido group and compoundsin which Y is azido and is reacted with a dipoloarophile may be preparedas described in British Patents Nos. 1,057,883 and 1,211,694. Compoundsof the invention wherein Y is the residue of a nucleophilic may also beprepared by the reaction of a 3-halomethyl-cephalosporin with any of thenucleophiles disclosed in the above references, such a process beingdescribed in Belgian Patent No. 719,711. Where Y is a hydroxy group thecompound may be prepared by the methods described in British Patent No.1,121,308.

Compounds having a vinyl or substituted vinyl group as 3-positionsubstituent may be obtained by the method described in Belgian PatentNo. 761,897.

Where Y is a halogen (i.e. chlorine, bromine or iodine) ceph-3-emstarting compounds may be prepared by halogenation of a7β-acylamido-3-methylceph-3-em-4-carboxylic acid ester 1β-oxide followedby reduction of the 1β-oxide group later in the sequence as described inBelgian Patent No. 755,256.

The corresponding ceph-2-em compounds may be prepared by the method ofDutch published Patent Application No. 6902013 by reaction of aceph-2-em-3-methyl compound with N-bromo-succinimide to yield theceph-2-em-3-bromomethyl compound.

Where Y is a hydrogen atom the compound may be prepared by the methoddescribed in British Patent No. 957,569 or from a penicillin compound bythe method described in U.S. Pat. No. 3,275,626 and Belgian Patents Nos.747,119 and 747,120.

Cephalosporin compounds possessing an acyloxymethyl group as 3-positionsubstituent may be prepared by any convenient method e.g. they may beprepared from a cephalosporin having a 3--CH₂ Y group where Y=OH or theresidue of the acid H Y which has a pKa of not more than 4.0 andpreferably not more than 3.5 (as measured in water at 25° C.).

The group Y may be a chlorine, bromine or iodine atom, formyloxy or anacetoxy group having at least one electronwithdrawing substituent on theα-carbon atom or a nuclear substituted benzoyloxy group, the nuclearsubstituent being of the electron withdrawing type as described inBritish Patent No. 1,241,657 and the nucleophilic displacement reactionto introduce the desired 3-position substituent may be carried out asdescribed in our aforesaid British Patent No. 1,241,657.

Alternatively where Y is hydroxy the desired 3-acyloxymethylcephalosporin may be obtained by acylation as described in BritishPatent No. 1,141,293. In British Patent No. 1,141,293 there is describeda process for the preparation of a Δ³ -cephalosporin having a3-acyloxymethyl substituent from a corresponding 3-hydroxymethylanalogue which comprises aralkylating the 4-carboxy group, acylating the3-hydroxymethyl group of the protected compound and subsequentlyremoving the aralkyl group.

The acylation may be carried out by any convenient method using forexample an acid chloride, acid anhydride or a mixed acid anhydride asthe acylating agent preferably in the presence of an organic base suchas pyridine and carrying out the reaction in solution in an inertanhydrous solvent for example methylene chloride. Alternatively theacylation may be carried out in aqueous acetone/sodium bicarbonatesolution. The preferred acylating agent is the acid chloride.

The acylation reaction should be effected as rapidly as possible, sinceunder the conditions of the acylation rearrangement to the Δ²-derivative can occur, particularly when an aroyloxy group is beingintroduced at the exocyclic methylene group at the 3-position.

Compounds of the formula (VII) may be employed as esters; those offormula (XI) are esters. One may also use the free amino acid or an acidaddition salt of the free amino acid or ester thereof. Salts which maybe used include acid addition salts e.g. with hydrochloric, hydrobromic,sulphuric, nitric, phosphoric, toluene-p-sulphonic and methane sulphonicacids.

The ester may be formed with an alcohol, phenol, silanol or stannanolhaving up to 20 carbon atoms which may readily be split off at a laterstage of the overall reaction.

Any esterifying group substituting the 4-carboxyl group of a compound offormula (VII), (XI) or (XII) is preferably formed with an alcohol(aliphatic or araliphatic), phenol, silanol, stannanol or acid which mayreadily be split off at a later stage of the reaction.

Suitable esters thus include compounds containing as ester group a groupselected from the following list which is not intended to be anexhaustive list of possible ester groups.

(i) --COOCR^(a) R^(b) R^(c) wherein at least one of R^(a), R^(b) andR^(c) is an electron-donor e.g. p-methoxyphenyl, 2,4,6-trimethylphenyl,9-anthryl, methoxy, acetoxy, or fur-2yl. The remaining R^(a), R^(b) andR^(c) groups may be hydrogen or organic substituting groups. Suitableester groups of this type include p-methoxybenzyloxycarbonyl and2,4,6-trimethylbenzyloxy carbonyl.

(ii) --COOCR^(a) R^(b) R^(c) wherein at least one of R^(a), R^(b) andR^(c) is an electron-attracting group e.g. benzoyl, p-nitrophenyl,4-pyridyl, trichloromethyl, tribromomethyl, iodomethyl, cyanomethyl,ethoxycarbonylmethyl, arylsulphonylmethyl, 2-dimethylsulphoniumethyl,o-nitrophenyl or cyano. The remaining R^(a), R^(b), and R^(c) groups maybe hydrogen or organic substituting groups. Suitable esters of this typeinclude benzoylmethoxycarbonyl, p-nitrobenzyloxycarbonyl,4-pyridylmethoxycarbonyl, 2,2,2-trichloroethoxycarbonyl and2,2,2-tribromoethoxycarbonyl.

(iii) --COOCR^(a) R^(b) R^(c) wherein at least two of R^(a), R^(b) andR^(c) are hydrocarbon such as alkyl e.g. methyl or ethyl, or aryl e.g.phenyl and the remaining R^(a), R^(b) and R^(c) group, if there is one,is hydrogen. Suitable esters of this type include t-butyloxycarbonyl,t-amyloxycarbonyl, diphenylmethoxycarbonyl and triphenylmethoxycarbonyl.

(iv) --COOR^(d) wherein R^(d) is adamantyl, 2-benzyloxyphenyl,4-methylthiophenyl, tetrahydrofur-2-yl or tetrahydropyran-2-yl.

(v) Silyloxycarbonyl groups obtained by reaction of a carboxyl groupwith a derivative of a silanol. The derivative of a silanol isconveniently a halosilane or a silazane of the formula R⁴ ₃ SiX; R⁴ ₂SiX₂ ; R⁴ ₃ Si.NR⁴ ₂ ; R⁴ ₃ Si.NH.SiR⁴ ₃ ; R⁴ ₃ Si.NH.COR⁴ ; R⁴ ₃Si.NH.CO.NH.SiR⁴ ₃ ; R⁴ NH.CO.NR⁴.SiR⁴ ₃ ; or R⁴ C(OSiR⁴ ₃): NSiR⁴ ₃where X is a halogen and the various groups R⁴, which can be the same ordifferent, represent hydrogen atoms or alkyl, e.g. methyl, ethyl,n-propyl, iso-propyl; aryl, e.g. phenyl; or aralkyl e.g. benzyl groups.Preferred derivatives of silanols are silyl chlorides such as forexample trimethylchlorosilane and dimethyldichlorosilane.

The carboxyl group may be regenerated from an ester by any of the usualmethods, for example, acid- and basecatalysed hydrolysis is generallyapplicable, as well as enzymically-catalysed hydrolyses; however,aqueous mixtures may be poor solvents for these compounds and they maycause isomerizations, rearrangements, sidereactions, and generaldestruction, so that special methods may be desirable.

Five suitable methods of deesterification are

(1) Reactions with Lewis acids.

Suitable Lewis acids for reaction with the esters includetrifluoroacetic acid, formic acid, hydrochloric acid in acetic acid,zinc bromide in benzene and aqueous solutions or suspensions of mercuriccompounds. The reaction with the Lewis acid may be facilitated byaddition of a nucleophile such as anisole.

(2) Reduction.

Suitable systems for effecting reduction are zinc/acetic acid,zinc/formic acid, zinc/lower alcohol, zinc/pyridine, palladised-charcoaland hydrogen, and sodium and liquid ammonia.

(3) Attack by nucleophiles.

Suitable nucleophiles are those containing a nucleophilic oxygen orsulphur atom for example alcohols, mercaptans and water.

(4) Oxidative methods, for example, those which involve the use ofhydrogen peroxide and acetic acid.

(5) Irradiation.

Where at the end of a given preparative sequence compounds are obtainedwherein B is >S→O and a compound is desired in which B is >S conversionto a sulphide may for example, be effected by reduction of thecorresponding acyloxysulphonium or alkyloxysulphonium salt prepared insitu by reaction with e.g. acetyl chloride in the case of anacetoxysulphonium salt, reduction being effected by, for example, sodiumdithionite or by iodide ion as in a solution of potassium iodide in awater miscible solvent e.g. acetic acid, tetrahydrofuran, dioxan,dimethylformamide or dimethylacetamide. The reaction may be effected ata temperature of -20° to +50° C.

Alternatively, reduction of the 1-sulphinyl group may be effected byphosphorus trichloride or tribromide in solvents such as methylenechloride, dimethylformamide or tetrahydrofuran, preferably at atemperature of -20° C. to +50° C.

Where the resultant compound is a ceph-2-em-4-ester the desiredceph-3-em compound may be obtained by treatment of the former with abase.

The acid (VI) to which the acylating agent corresponds may be obtainedby reacting the glyoxylic acid.

    R.CO.COOH

(where R has the above defined meaning) or an ester thereof with R^(a)O.NH₂ (R^(a) having the above defined meaning).

The resulting acid or ester may then be separated into its syn and antiisomers e.g. by crystallisation, chromatography or distillation,followed when necessary by hydrolysis of the ester.

Alternatively the acid (VI) where R^(a) =H may be obtained by reactingan ester of the acid

    R.CH.sub.2 COOH

(where R has the above defined meaning) with an inorganic or organicnitrosating agent e.g. an alkyl nitrite such as isopropyl nitrite, ornitrosyl chloride in the presence of an acid or base. We prefer that anexcess of the nitrosating agent be used e.g. a molar excess. Thereafterthe ester group is removed, if necessary.

Syn and anti isomers may be distinguished by appropriate techniques,e.g. by their ultraviolet spectra, by thin layer or paper chromatographyor by their nuclear magnetic resonance spectra. For example, for DMSO-d₆solution compounds of Formula I exhibit the doublet for the amide NH ata lower field for the syn-isomers than for the anti-isomers). Thesefactors may be employed in monitoring reactions.

The antibacterial compounds according to the invention may be formulatedfor administration in any convenient way, by analogy with otherantibiotics and the invention therefore includes within its scope apharmaceutical composition comprising an antibacterial compound offormula I or a non-toxic derivative e.g. salt thereof (as hereindefined) adopted for use in human or veterinary medicine. Suchcompositions may be presented for use in conventional manner with theaid of any necessary pharmaceutical carriers or excipient.

The antibacterial compounds according to the invention may be formulatedfor injection and may be presented in unit dose form in ampoules, or inmultidose containers with an added preservative. The compositions maytake such forms as suspensions, solutions, emulsions in oily or aqueousvehiclels, and may contain formulatory agents such as suspending,stabilising and/or dispersing agents. Alternatively the activeingredient may be in powder form for reconstitution with a suitablevehicle, e.g. sterile, pyrogen-free water, before use.

The compositions may be presented in a form suitable for absorption bythe gastro-intestinal tract. Tablets and capsules for oraladministration may be in unit dose presentation form, and may containconventional excipients such as binding agents, for example, syrup,acacia, gelatin, sorbitol, tragacanth, or polyvinyl-pyrollidone;fillers, for example lactose, sugar, maize-starch, calcium phosphate,sorbitol or glycine; lubricants, for example, magnesium stearate, talc,polyethylene glycol, silica; disintegrants, for example, potato starchor acceptable wetting agents such as sodium sulphate. The tablets may becoated according to methods well known in the art. Oral liquidpreparation may be in the form of aqueous or oily suspensions,solutions, emulsions, syrups, elixirs, etc. or may be presented as a dryproduct, for reconstitution with water or other suitable vehicle beforeuse. Such liquid preparations may contain conventional additives such assuspending agents, for example, sorbitol syrup, methyl cellulose,glucose/sugar syrup, gelatin, hydroxyethylcellulose, carboxymethylcellulose, aluminium stearate gel or hydrogenated edible fats,emulsifying agents, for example, lecithin, sorbitan monooleate oracacia; non-aqueous vehicles which may include edible oils, for example,almond oil, fractionated coconut oil, oily esters, propylene glycol, orethyl alcohol; preservatives, for example, methyl or propylp-hydroxybenzoates or sorbic acid. Suppositories will containconventional suppository bases, e.g. cocoa butter or other glyceride.

The composition may also be prepared in suitable forms for absorptionthrough the mucous membranes of the nose and throat or bronchial tissuesand may conveniently take the form of powder or liquid sprays orinhalants, lozenges, throat paints etc. For medication of the eyes orears, the preparations may be presented as individual capsules, inliquid or semi-liquid form, or may be used as drops etc. Topicalapplications may be formulated in hydrophobic or hydrophilic bases asointments, creams, lotions, paints, powders etc.

For veterinary medicine the composition, may, for example, be formulatedas an intramammary preparation in either long acting or quick-releasebases.

The compositions may contain from 0.1% upwards, preferably from 10-60%of the active material, depending on the method of administration. Wherethe compositions comprise dosage units, each unit will preferablycontain 60-500 mg. of the active ingredient. The dosage as employed foradult human treatment will preferably range from 100-3000 mg. forinstance 1500 mg per day, depending on the route and frequency ofadministration.

The compounds according to the invention may be administered incombination with other therapeutic agents such as antibiotics, forexample other cephalosporins, the penicillins or tetracyclines.

The following examples illustrate the invention.

2-HYDROXYIMINO-ACETIC ACIDS AND DERIVATIVES PREPARATION 12-Hydroxyimino(thien-2-yl)acetic acid (syn-isomer)

A cooled solution of hydroxylamine hydrochloride (0.884 g) and sodiumbicarbonate (1.08 g) in water (20 ml.) was added to a cooled (0°)solution of thien-2-yl-glyoxylic acid (2.0 g) and sodium bicarbonate(1.08 g) in water (20 ml.). After two days at 20° the solution wasextracted with ether, cooled and acidified with concentratedhydrochloric acid. The resulting white solid was filtered off (0.564 g)and the filtrate was then thoroughly extracted with ether. The combinedextracts were washed with brine, dried and concentrated. The solidresidue was triturated with benzene to give the oxime (syn-isomer) (1.05g; 51%), m.p. 132°, λ_(max). (ethanol) 284 nm (ε 9,500), λ_(max).(Nujol) 2590 and 1706 (CO₂ H) and 1655 cm⁻¹ (C=N), τ (DMSO-d6), -2.5 to-0.5 (broad multiplet; N--OH and COOH), 2.36 (multiplet; thienyl C-5 H)and 2.82 (multiplet; thienyl C-3 H and C-4 H).

PREPARATION 2 2-Dichloroacetoxyiminophenylacetic acid (syn-isomer).

To a mixture of methylene chloride (45 ml) and dichloroacetyl chloride(10 ml) was added portionwise with stirring 2-hydroxyiminophenylaceticacid (syn-isomer) (5 g) in portions over about fifteen minutes. Thereaction mixture became solid, and was stirred for one hour at roomtemperature after the addition was complete. The reaction was dilutedwith petroleum (b.p. 40°-60°), filtered, and the solid washed severaltimes with petroleum spirit to remove residual acid chloride. The solidwas dried under vacuum, giving 2-dichloroacetoxyiminophenylacetic acid(syn-isomer)(8.0 g; 96%), m.p. 115°, ν_(max). (CHBr₃) 3470 and 1750(--CO₂ H), 1765 cm.⁻¹ (ester), τ (CDCl₃) values include 2.0-2.7(multiplet; aromatic protons), 3.85 (singlet; --CHCl₂).

PREPARATION 3 2-Dichloroacetoxyimino-(thien-2-yl)acetic acid(syn-isomer)

2-Hydroxyimino-(thien-2-yl)acetic acid (syn-isomer) (38 g.) was addedportionwise to a stirred solution of dichloroacetyl chloride (70 ml.) indry methylene chloride (350 ml.) at 20°. Stirring was continued andafter ca. 20 mins. white fibrous crystals formed. The suspension wasstirred for 10 mins. longer and then filtered. The solid was washed withmethylene chloride and petroleum to give the title acid (38.5 g., 61%)λ_(max). (EtOH) 262.5 (ε 9,520), 291 nm (ε 8,580).

PREPARATION 4 2-Dichloroacetoxyimino-(4-chlorophenyl)acetic acid(syn-isomer)

To a solution of dichloroacetyl chloride (1.8 ml.) in methylene chloride(15 ml.) was added 2-hydroxyimino-(4-chlorophenyl)acetic acid(anti-isomer) (1.5 g.) and the suspension stirred for two hours at roomtemperature. During this time most of the material dissolved. The solidwas removed, washed with petroleum (b.p. 40°-60°) and the washings andfiltrate were combined, kept at 5° overnight and the resulting solid wascollected and dried to give the title acid (2.0 g; 85%), m.p. 80°,λ_(max). (EtOH) 258 nm (ε 12,280), λ_(max). (Nujol) 1774 (ester), 1750and 1722 cm.⁻¹ (CO₂ H).

PREPARATION 5 2-Dichloroacetoxyiminonaphth-1'-ylacetyl chloride(syn-isomer)

To a solution of 2-hydroxyiminonaphth-1'-ylacetic acid (syn-isomer)(0.375 g) in ethyl acetate (10 ml.) at 0° was added dichloroacetylchloride (0.2 ml.) and the solution was stirred for thirty minutes at0°. After the addition of phosphorus pentachloride (0.36 g.), themixture was stirred for ninety minutes at 0°. The solvent was evaporatedat a low temperature (ca. 5°) and toluene evaporated from the residue,at ca. 5°. The remaining oil was dissolved in ethyl acetate (5 ml.) andused without further purification.

PREPARATION 6 2-Dichloroacetoxyiminophenylacetyl chloride (syn-isomer)

To a suspension of 2-dichloroacetoxyiminophenylacetic acid (syn-isomer)(0.276 g) in methylene chloride (10 ml.) was added phosphoruspentachloride (0.208 g) and the mixture was stirred for one hour at roomtemperature, during which time solution took place. After removal ofsolvent under reduced pressure, benzene was evaporated from the residue,and the resulting oil freed from solvent under vacuum, giving2-dichloroacetoxyiminophenylacetyl chloride (syn-isomer) (0.29 g.,100%), ν_(max). (liquid film) 1770 cm.⁻¹ (COCl and CO₂ R).

PREPARATION 7 2-Dichloroacetoxyimino-(thien-2-yl)acetyl chloride(syn-isomer)

A 0.3 M solution of phosphorus pentachloride in methylene chloride (179ml.) was added dropwise during 15 minutes to a stirred and cooled (0°)suspension of syn-2-hydroxyiminothien-2-ylacetic acid (16.7 g.) in drymethylene chloride (340 ml.). After 5 minutes the solution wasconcentrated under reduced pressure and at low temperature. The redresidual oil was azeotroped with benzene, dissolved in ethyl acetate andused without further purification.

PREPARATION 8 2-Hydroxyiminonaphth-1'-ylacetic acid (syn andanti-isomers)

To a solution of hydroxylamine hydrochloride (4.62 g.) in methanol (40ml.) was added phenolphthalein then methanolic sodium methoxide solution(approx. 5% w/v) until a pink end-point was reached. A crystal ofhydroxylamine hydrochloride was added to discharge the pink colour, andthe solution was filtered to remove sodium chloride.Naphth-1'-ylglyoxylic acid (10.0 g) was added and the mixture heated atreflux for thirty minutes. It was then evaporated to dryness, water (50ml.) added, and the pH adjusted to 1 with 2 N-hydrochloric acid. Theresulting suspension was extracted with ethyl acetate, the combinedextracts washed with water, dried and evaporated to give a pale yellowsolid which was recrystallised from benzene-petroleum (b.p. 60°-80°) togive 2-hydroxyiminonaph-1'-ylacetic acid (anti-isomer) (2.7 g; 25%),m.p. 159°, λ_(max). (EtOH) 279 nm (ε 5,940) ν_(max). (Nujol) 3245 (OH),1701, 1712 cm.⁻¹ (CO₂ H) τ (DMSO-d6) -3.0 to -2.2 (broad signal; OH)1.8-2.7 (multiplet; aromatic protons).

The mother liquor from the recrystallisation was evaporated to dryness,the solid (2.2 g.) was treated with a slight excess of etherealdiazomethane and the yellow colouration discharged by addition of thecrude 2-hydroxyiminonaphth-1'-ylacetic acid. The ethereal solution waswashed with saturated sodium bicarbonate solution, dried and evaporatedto give a mixture of syn- and anti-methyl 2-hydroxyiminonaphth-1'-ylacetates (2.3 g.) The mixture (2.0 g) was dissolved in ethyl acetate andapplied to eight Merck silica gel chromatoplates (20 cm×20 cm.). Theplates were developed with ether:petroleum (b.p. 40°-60°) (1:2) and themajor component, which had the higher R_(f), was eluted with ethylacetate, giving methyl 2-hydroxyiminonaphth-1'-yl acetate (syn-isomer)(0.75 g; 34%) m.p. 110°-111°, λ_(max) (EtOH) 293.5 nm (ε 8150), ν_(max).(CHBr₃) 3550 (OH) and 1737 cm.⁻¹ (ester), τ (CDCl₃) values include1.9-2.85 (multiplet; aromatic protons), 6.16 (singlet; CH₃). A solutionof the ester (1.10 g.) in N-sodium hydroxide (15 ml.) was allowed tostand for one hour, then washed with ether, acidified (2 N-hydrochloricacid) and extracted with ethyl acetate. The combined extracts werewashed with water, dried, and evaporated to give a solid which wastriturated with petroleum spirit (b.p. 40°-60°), filtered and dried,giving the title acid (syn-isomer) (0.89 g, 86%), m.p. 111°-112°,λ_(max). (EtOH) 292 nm (ε 7,400), ν_(max). (Nujol) 2630 (OH), 1678 (CO₂H).

PREPARATION 9 Ethyl thien-3-yl glyoxylate

To a solution of n-butyl lithium in ether (265 ml.) at -70° was added,with vigorous stirring, a solution of 3-bromothiophene (41 g.) in ether(50 ml) dropwise over 30 minutes, in an atmosphere of nitrogen. Theresulting slurry was stirred at -70° for 5 minutes, then added withvigorous stirring to a solution of diethyl oxalate (110 g) in ether (220ml.), the temperature being maintained below -70° throughout theaddition. After the addition, the temperature of the solution wasallowed to rise to room temperature and the reaction was stirred forthree hours and then poured into 2 N-hydrochloric acid. The organicphase was separated and was combined with two ethereal extracts of theaqueous phase. The combined extracts were dried and evaporated to givean oil which was fractionated under reduced pressure. After distillationof excess diethyl oxalate at 6370.1 mm, the title ester was collected,b.p. 110°/0.1 mm. (12 g; 26%), ν_(max). 1720 cm⁻¹ (ester) τ (CDCl₃)1.43, 2.28, 2.61, (thienyl protons), 5.56 (quartet J 8 Hz; CH₂ CH₃),8.58 (triplet; J 8 Hz; CH₂ CH₃).

PREPARATION 10 Thien-3-yl-glyoxylic acid

To a mixture of ethyl thien-3-yl-glyoxylate (10 g) and 2 N-sodiumhydroxide (50 ml) was added sufficient methanol to produce a homogeneoussolution, and the reaction was allowed to stand at room temperature forone hour. The solution was poured into water, extracted with ether,acidified with 2 N-hydrochloric acid and extracted with ether. Thecombined extracts were dried and evaporated to give an oil which wastriturated with benzene-petroleum ether, and the resulting solidfiltered and dried (7.5 g; 88%), m.p. 63°, ν_(max). (Nujol) 3600 and1702 cm⁻¹ (CO₂ H), τ (DMSO-d₆) values include 1.29, 2.21, 2.38(thien-3-yl protons).

PREPARATION 11 2-Hydroxyimino-2(thien-3-yl)-acetic acids

To a stirred solution of hydroxylamine hydrochloride (1.15 g) inmethanol (15 mls) containing phenolphthalein (2 drops) was added asolution of sodium methoxide in methanol until a pink colour wasobtained. After the addition of one crystal of hydroxylaminehydrochloride to discharge the pink colour the mixture was added to asolution of thien-3-yl-glyoxylic acid (2.0 g) in methanol (10 mls) andrefluxed for 1 hr. The methanol was evaporated to a small volume and theresidue was partitioned between ethyl acetate and water. The aqueouslayer was acidified to pH 1 with 2 N-hydrochloric acid and extractedwith ethyl acetate. After drying, the ethyl acetate was evaporated toyield a white solid consisting of isomeric 2-hydroxyimino-2-(thien-3-yl)acetic acids, λ_(max). (ethanol) 254.5 mm (ε 9,700), ν_(max). (CHBr₃)3540 (OH unbonded), 3200 (OH bonded) and 1750 cm.⁻¹ (COOH) τ (DMSOd₆)values include 1.78 [multiplet; thienyl protons (anti isomer)], 2.2 to2.7 (complex multiplet; thienyl protons).

PREPARATION 12 2-Dichloroacetoxyimino-2-(thien-3-yl)acetyl chloride (synisomer)

2-Hydroxyimino-2-(thien-3-yl)acetic (1.03 g) mixture was addedportionwise to a stirred solution of dichloroacetyl chloride (1.8 mls)in dry methylene chloride (10 mls). After 30 mins. an excess of petrol(b.p. 40°-60°) was added to the reaction and the precipitated whitesolid was collected, washed with petrol (b.p. 40°-60°) and dried toyield 2-dichloroacetoxyimino-2-(thien-3-yl)acetic acid (syn isomer) (1.6gms, 94%) which was suspended in dry methylene chloride and ice-cooled.To the suspension was added dropwise a freshly prepared solution ofphosphorus pentachloride (1 equiv.) in dry methylene chloride. When allcomponents were in solution the solvent was removed in vacuo at lowtemperature and the residual oil was azeotroped with benzene to give2-dichloroacetoxyimino-2-(thien-3-yl)acetyl chloride (syn) as a paleyellow oil which was used directly.

PREPARATION 13 2-Hydroxyimino-2-(fur-2-yl)acetic acids

To a stirred solution of hydroxylamine hydrochloride (1.94 gms) inmethanol (30 mls) containing phenolphthalein (2 drops) was added asolution of sodium methoxide in methanol until a pink colour wasobtained. After the addition of one crystal of hydroxylaminehydrochloride to discharge the pink colour the mixture was added to asolution of fur-2-ylglyoxylic acid (3.0 gm) in methanol (10 mls) andrefluxed for 1 hr. The methanol was evaporated to a small volume andpartitioned between ethyl acetate and water. The aqueous layer wasacidified to pH 1 with 2 N-hydrochloric acid and extracted with ethylacetate. After drying, the solvent was evaporated to yield a yellowsolid which was collected, washed with petrol (b.p. 40°-60°) and driedto yield an isomeric mixture of 2-hydroxyimino-2-(fur-2-yl)acetic acids(2.7 gms., 81%) λ_(max) (ethanol) 271.5 nm (ε, 12,400), ν_(max). (CHBr₃)3550 (OH), 1740 and 1705 cm.⁻¹ (CO₂ H), τ (DMSO d₆) values include 2.62[doublet; J 4 Hz, furyl(anti isomer) C 3-H], 2.14 and 3.32 (complexsignals, remaining furyl protons).

PREPARATION 14 2-Dichloroacetoxyimino-2-(fur-2-yl)acetyl chloride (syn)

2-Hydroxyimino-2-(fur-2-yl)acetic acid (1.38 g) mixture was addedportionwise to an ice cold solution of dichloroacetyl chloride (2.8mls.) in dry methylene chloride (14 mls.). After 15 mins stirring awhite precipitate was formed which was collected, washed successivelywith cold dry methylene chloride and petrol (b.p. 40°-60°) and dried toyield 2-dichloroacetoxyimino-2-(fur-2-yl)acetic acid (syn isomer) (1.5g, 63%).

To an ice-cold stirred suspension of2-dichloroacetoxyimino-2-(fur-2-yl)acetic acid (1.5 g) in dry methylenechloride (70 mls) was added dropwise a freshly prepared solution ofphosphorus pentachloride (1.0 equiv.) in methylene chloride. Whensolution was complete the solvent was evaporated at low temperature andthe residual oil azeotroped with benzene to give2-dichloroacetoxyimino-2(fur-2-yl)acetyl chloride (syn-isomer) as a paleyellow oil which was used directly.

EXAMPLE 1 (a) t-Butyl3-acetoxymethyl-7β-[2-hydroxyimino-2-phenylacetamido]-ceph-3-cm-4-carboxylate(syn-isomer).

To a solution of t-butyl 3-acetoxymethyl-7β-aminoceph-3-em-4-carboxylate(3.28 g) and dicyclohexylcarbodiimide (2.48 g) in methylene chloride (60ml.) and dimethylformamide (20 ml.) was added, dropwise with stirring atroom temperature, a solution of 2-hydroxyiminophenylacetic acid(syn-isomer)(Ahmad and Spencer, Can J. Chem, 1961, 39, 1340) (1.65 g) indimethyl formamide (20 ml.) and the mixture was stirred at roomtemperature for 3 hours. After filtration to remove dicyclohexylurea,the solution was evaporated, the residue taken up in ether (50 ml.),filtered and washed successively with saturated sodium bicarbonatesolution, 2 N-hydrochloric acid and water. The extract was dried andevaporated to give the title ester as a foam which was dried undervacuum. Yield 1.6 g; 33.8%, ν_(max). (CHBr₃) 3570 (OH), 1786 (β-lactam)1740 and 1230 cm.⁻¹ (OAc), τ (CDCl₃) values include 2.2-2.7 (multiplet;aromatic protons), 7.93 (singlet; CH₃ CO), 8.46 (singlet; t-butylester).

(b)3-Acetoxymethyl-7β-[2-hydroxyimino-2-phenylacetamido]ceph-3-em-4-carboxylicacid (syn-isomer).

A solution of t-butyl3-acetoxymethyl-7β-[2-hydroxyimino-2-phenylacetamido]-ceph-3-em-4-carboxylate(syn-isomer) (1.45 g.) in trifluoroacetic acid (25 ml.) was allowed tostand at room temperature for 10 minutes. The trifluoroacetic acid wasevaporated under reduced pressure, the residue dissolved in ether (50ml.) and extracted with saturated aqueous sodium bicarbonate. Thecombined aqueous extracts were acidified (2 N hydrochloric acid) andextracted with ethyl acetate. The combined extracts were washed withwater, dried and evaporated. The residue was redissolved in ethylacetate (5 ml.) and added dropwise with stirring to petroleum (b.p.40°-60° C.; 500 ml.). The precipitated solid was filtered and dried,giving3-acetoxymethyl-7β-[2-hydroxyimino-2-phenylacetamido]-ceph-3-em-4-carboxylicacid (syn-isomer) (0.515 g; 42%), [α]_(D) +56° (c 0.5, DMSO), λ_(max).(EtOH) 253 nm (ε 16,600), ν_(max). (Nujol) 3380 (NH and OH), 1778(β-lactam), 1720 (CO₂ H and acetate), 1666 and 1540 cm.⁻¹ (CONH) τ(DMSO-d6) values include 0.32 (doublet, J 9 Hz; NH) 2.15-2.7 (multiplet;aromatic protons), 7.8 (singlet; CH₃ CO).

(c) Sodium3-Acetoxymethyl-7β-(2-hydroxyimino-2-phenylacetamido)-ceph-3-em-4-carboxylate(syn isomer)

To a solution of3-acetoxymethyl-7β-(2-hydroxyimino-2-phenylacetamido)ceph-3-em-4-carboxylicacid ethyl acetate solvate (syn-isomer) (0.5 g.) in ethyl acetate (50ml.) was added sodium 2-ethyl hexanoate (1-M solution in ethyl acetate,1 ml.). After stirring for fifteen minutes at room temperature the solidwas collected by filtration, washed with ethyl acetate and ether anddried to give the title sodium salt (0.35 g; 82%) [α]_(D) +98° (c 1DMSO), λ_(max). (pH 6.0 phosphate buffer) 253.5 nm (ε 18,400), ν_(max).(Nujol) 3280 (NH and OH), 1765 (β-lactam), 1740 (OCOCH₃), 1670 and 1550cm.⁻¹ (CONH), τ values include (DMSO-d₆) 0.24 (singlet, J 9 Hz; NH),2.28-2.72 (aromatic protons) 7.99 (singlet, OCOCH₃).

EXAMPLE 2 (a) t-Butyl 3-acetoxymethyl-7β-(2-dichloroacetoxyimino-2-phenylacetamido)-ceph-3-em-4-carboxylate (syn-isomer)

To a solution of t-butyl 3-acetoxymethyl-7β-aminoceph-3-em-4-carboxylate(3.28 g) in ethyl acetate (25 ml.) was added a solution of2-dichloroacetoxyimino-2-phenylacetyl chloride (syn-isomer) in ethylacetate (25 ml.) dropwise with stirring. The solution became warm and aprecipitate formed. After two hours, the solution was filtered, washedsuccessively with 2 N-hydrochloric acid, water, and saturated sodiumbicarbonate solution, dried, and evaporated to give a yellow foam whichsolidified on standing, and was triturated with petroleum spirit givingt-butyl3-acetoxymethyl-7β-(2-dichloroacetoxyimino-2-phenylacetamido)-ceph-3-em-4-carboxylate(4.0 g; 70%), ν_(max). (CHBr₃) 3420 (NH), 1796 (β-lactam), 1730 and 1230(acetate), 1700 and 1512 cm⁻¹ (CONH), τ (DMSO-d₆) values include 2.1-2.5(multiplet; aromatic protons), 2.98 (singlet; CHCl₂), 7.6 (singlet; CH₃CO), 8.5 (singlet; t-butyl ester).

(b)3-Acetoxymethyl-7β-(2-hydroxyimino-2-phenylacetamido)-ceph-3-em-4-carboxylicacid (syn-isomer).

A solution of t-butyl3-acetoxymethyl-7β-(2-dichloroacetoxyimino-2-phenylacetamido)-ceph-3-em-4-carboxylate(3.0 g) in trifluoroacetic acid (25 ml.) was allowed to stand at roomtemperature for ten minutes. The excess acid was removed under reducedpressure, and benzene evaporated from the residue, which was taken upinto ethyl acetate and extracted into saturated aqueous sodiumbicarbonate. The aqueous phase was washed with ethyl acetate, acidifiedand extracted with ethyl acetate. The extracts were combined, dried,concentrated to about 5 ml and added dropwise to petroleum (200 ml.).The solid which precipitated was filtered and dried, giving3-acetoxymethyl-7β-(2-hydroxyamino-2-phenylacetamido)ceph-3-em-4-carboxylicacid (syn-isomer) as a white solid (1.9 g; 88%) [α]_(D) +68° (c 0.8DMSO), λ_(max). (EtOH) 254 nm (ε 17,600), ν_(max). (Nujol) 3380 (NH andOH) 1778 (β-lactam), 1720 (CO₂ H and acetate), 1666 and 1540 cm⁻¹(CONH), τ(DMSO-d₆) values include 0.32 (doublet, J 9 Hz; NH ofsyn-isomer), 1.00 (doublet, J 9 Hz; NH of anti-isomer, comprising ca.10% of the product), 2.15-2.7 (multiplet; aromatic protons), 7.8(singlet; CH₃ CO).

EXAMPLE 3 Sodium 3-acetoxymethyl-7β-[2-hydroxyimino-2-(thien-2-yl)acetamido]ceph-3-em-4-carboxylate(syn-isomer) (a) 2-Dichloroacetoxyimino-2-(thien-2-yl)acetyl chloride(syn-isomer)

Phosphorus pentachloride (27.2 g.) was added portionwise during ca. 20minutes to a stirred and cooled (ice-bath) suspension of2-dichloroacetoxyimino-2-(thien-2-yl)acetic acid (syn-isomer) (37.0 g.)in methylene chloride (370 ml.). The mixture was stirred at 0° for afurther 30 minutes during which time all the solid dissolved. Afterremoval of the solvent under reduced pressure, benzene was evaporatedfrom the residue at 20°, and the process repeated to give2-dichloroacetoxyimino-2-(thien-2-yl)acetyl chloride (syn-isomer) as anoil that was used directly in the next stage.

(b) t-Butyl3-acetoxymethyl-7β-[2-dichloroacetoxyimino-2-(thien-2-yl)-acetamido]-ceph-3-em-4-carboxylate(syn-isomer).

A solution of 2-dichloroacetoxyimino-(thien-2-yl)acetyl chloride(syn-isomer) in ethyl acetate (300 ml.) was added to a stirred solutionof t-butyl 3-acetoxymethyl-7β-aminoceph-3-em-4-carboxylate (43 g) andpropylene oxide (34 ml.) in ethyl acetate (400 ml.) at 20°. Initially asolid precipitated out but it gradually redissolved. The temperature wasmaintained between 20° and 30° by alternately cooling and warming thesolution. After 4 hours the solution was washed with 2 N-hydrochloricacid, saturated sodium bicarbonate solution, water and brine, and wasdried and concentrated under reduced pressure to give the title ester asan oil that was used directly in the next stage.

(c)3-Acetoxymethyl-7β-[2-dichloroacetoxyimino-2-(thien-2-yl)acetamido]-ceph-3-em-4-carboxylicacid (syn-isomer)

A solution of t-butyl3-acetoxymethyl-7β-[2-dichloroacetoxyimino-(thien-2-yl)acetamido]ceph-3-em-4-carboxylate(syn-isomer) in anisole (20 ml.) was treated with trifluoroacetic acid(100 ml.). After 5 minutes at 20° the solution was concentrated underreduced pressure at 35°. Ethyl acetate was added and the solution wasagain concentrated, whereupon a solid separated out. Ethyl acetate wasevaporated from the residue three more times and the solid was collectedand washed with ether to give3-acetoxymethyl-7β-[2-dichloroacetoxyimino-2-(thien-2-yl)acetamido]ceph-3-em-4-carboxylicacid (syn-isomer) (37 g., 53%) λ_(max). (ethanol) 263 nm (ε14,800),τ(DMSO-d6) values include -0.19 (doublet, J 8 Hz; NH), 3.02 (singlet,CHCl₂), 7.94 (singlet, OCOCH₃).

(d)3-Acetoxymethyl-7β-[2-hydroxyimino-2-(thien-2-yl)acetamido]ceph-3-em-4-carboxylicacid (syn-isomer)

3-Acetoxymethyl-7β-[2-dichloroacetoxyimino-2-(thien-2-yl)acetamido]ceph-3-em-4-carboxylicacid (syn-isomer) (36.1 g.) was partitioned between ethyl acetate (ca.250 ml.) and saturated sodium bicarbonate solution (200 ml.). The layerswere separated and the ethyl acetate solution was extracted twice morewith sodium bicarbonate solution. The combined extracts were washed withethyl acetate, then covered with ethyl acetate and carefully acidifiedwith concentrated hydrochloric acid. The layers were separated and theaqueous layer was extracted twice more with ethyl acetate. The combinedextracts were washed with water and brine, dried and concentrated underreduced pressure to a small volume (ca. 60 ml.), which was addeddropwise to stirred petroleum (b.p. 40°-60°, ca. 1500 ml.). Theresulting buff-coloured solid was collected to give3-acetoxymethyl-7β-[2-hydroxyimino-2-(thien-2-yl)acetamido]ceph-3-em-4-carboxylicacid (syn isomer) (27.5 g., 95%).

(e) Sodium3-acetoxymethyl-7β-[2-hydroxyimino-(thien-2-yl)acetamido]-ceph-3-em-4-carboxylate(syn-isomer).

A solution of sodium 2-ethylhexoate (12.6 g.) in ethyl acetate (120 ml.)was added to a stirred solution of3-acetoxymethyl-7β-[2-hydroxyimino-2-(thien-2-yl)acetamido]ceph-3-em-4-carboxylicacid (syn-isomer) (27.3 g.) in ethyl acetate (270 ml.) at 20°. Themixture was cooled to 0° for 1 hour and the pale buff solid was filteredoff, washed with ethyl acetate and ether and dried in vacuo to give thetitle sodium salt (25.1 g., 87.5%), [α]_(D) +78.5° (c 1.1 DMSO),λ_(max). (pH 6 buffer) 261 nm (ε15,200), λ_(inflexion) 285 nm (ε10,200),τ (D₂ O) 2.41 (d, 5 Hz; thienyl C-3 H or C-5 H) 2.64 (d, J 4 Hz; thienylC-5 H or C-3 H), 2.84 (dd, J4 and 5 Hz; thienyl C-4H), 4.12 (d, J 5 Hz;C-7H), 4.78 (d, J 5 Hz; C-6H); 5.08 and 5.28 (2ds, branches of quartet,J 12 Hz; C-3 CH₂), 6.33 and 6.65 (2ds, branches of quartet, J 18 Hz; C-2CH₂) and 7.91 (s; OCOCH₃).

EXAMPLE 47β-(2-Hydroxyimino-2-phenylacetamido)-3-(5-methyl-1,3,4-thiadiazol-2-yl)thiomethylceph-3-em-4-carboxylicacid (syn-isomer). (a)7β-Formamido-3-(5-methyl-1,3,4-thiadiazol-2-yl)thiomethylceph-3-em-4-carboxylicacid

A solution of 7β-formamido-3-acetoxymethylceph-3-em-4-carboxylic acid(24.0 g) and 5-methyl-1,3,4-thiadiazole-2-thiol (10.56 g) in M. pH 6.4phosphate buffer (600 ml.) was heated at 60° for 41/2 hours. Thesolution was cooled to 20° and the pH was adjusted from 6 to 5 withphosphoric acid. The solution was extracted with ethyl acetate the pH ofthe aqueous layer was taken to 2 with phosphoric acid and the productwas extracted into ethyl acetate. The extract was washed with brine,dried and concentrated to a low volume under reduced pressure and addedto stirred petroleum. The resulting solid was collected and dried togive the title compound (9.36 g.) [α]_(D) -98° (c 1 DMSO), λ_(max). (pH6 buffer) 271 nm (ε11,400), τ values (D₂ O+NaHCO₃) include 1.74 (s;CHO), 4.30 (d, J 4.5 Hz; C-7 H), 4.88 (d, J 4.5 Hz; C-6 H) and 7.25 (s;CH₃).

(b) Diphenylmethyl7β-formamido-3-(5-methyl-1,3,4-thiadiazol-2-yl)thiomethylceph-3-em-4-carboxylate

A solution of7β-formamido-3-(5-methyl-1,3,4-thiadiazol-2-yl)thiomethylceph-3-em-4-carboxylicacid (8.5 g) in tetrahydrofuran (300 ml.) was treated with an excess ofa solution of diphenyldiazomethane in petroleum (300 ml.) and themixture was kept at 20° for 16 hours. A few drops of acetic acid wereadded and solvents were removed under reduced pressure. The resultingyellow syrup was dissolved in ethyl acetate and washed with sodiumbicarbonate solution. A solid (7.5 g) precipitated and was dried invacuo. A sample (5.77 g) of the wet solid was dissolved in methylenechloride, and the solution was dried and concentrated under reducedpressure. The residue was crystallised from methanol to give the titleester (5.08 g), m.p. 108° (decomp.), λ_(max). (EtOH) 268 nm (ε12,400), τ(CDCl₃ +a little DMSO-d6) values include 1.50 (d, J 9 Hz; NH), 1.72 (s;HCO), 6.30 (singlet; C-2 CH₂) and 7.31 (singlet; CH₃).

(c) Diphenylmethyl7β-amino-3-(5-methyl-1,3,4-thiadiazol-2-yl)thiomethylceph-3-em-4-carboxylatehydrochloride

Phosphorus oxychloride (1.8 ml.) was added dropwise during 2 minutes toa stirred and cooled (0°) suspension of diphenylmethyl7β-formamido-3-(5-methyl-1,3,4-thiadiazol-2-yl)thiomethylceph-3-em-4-carboxylate(4.1 g) in dry methanol. After 30 minutes the yellow solution wasconcentrated under reduced pressure. Ethyl acetate was added to theresidue and the resulting solid was collected and washed with ether togive the title hydrochloride λ_(max). (EtOH) 266 nm (ε11,300), ν_(max).(Nujol) include 2590 (NH₃ ⁺), 1778 (β-lactam) and 1710 cm.⁻¹ (ester), τvalues (DMSO-d₆) include 0.50 (broad m; NH₃), 2.3-2.7 (m; phenylprotons), 3.02 (s; CHPh₂), 4.66+4.76 (m; C-7 H and C-6 H), 5.39+5.69(2ds, branches of quartet, J 13 Hz; C-3 CH₂ S). 6.15 (singlet; C-2 CH₂ )and 7.36 (singlet; CH₃).

(d) Diphenylmethyl7β-amino-3-(5-methyl-1,3,4-thiadiazol-2-yl)thiomethylceph-3-em-4-carboxylate

Diphenylmethyl7β-amino-3-(5-methyl-1,3,4-thiadiazol-2-yl)thiomethylceph-3-em-4-carboxylatehydrochloride (5 g) was shaken with saturated sodium bicarbonatesolution and ethyl acetate. The layers were separated and the aqueouslayer was re-extracted with ethyl acetate. The combined ethyl acetateextracts were washed with sodium bicarbonate solution and brine, driedand concentrated under reduced pressure. The residue was crystallisedfrom ethyl acetate-ether to give the title free base (2.75 g) m.p. 152°(decomp.), λ_(max). (EtOH) 268 nm (ε9,000), λ_(max). (CHBr₃) includes3400 and 3335 (NH₂), 1772 (β-lactam), 1720 (ester), τ (CDCl₃) valuesinclude 2.50-2.75 (m; phenyl protons), 3.00 (s; CHPh₂), 7.31 (singlet;CH₃) and 8.22 (s; NH₂).

(e)7β-(2-Hydroxyimino-2-phenylacetamido)-3-(5-methyl-1,3,4-thiadiazol-2-yl)thiomethylceph-3-em-4-carboxylicacid (syn-isomer)

A 1-molar solution of 2-dichloroacetoxyimino-2-phenylacetyl chloride(syn-isomer) in ethyl acetate (3.8 ml.) was added during 5 minutes to astirred suspension of diphenylmethyl7β-amino-3-(5-methyl-1,3,4-thiadiazol-2-yl)thiomethylceph-3-em-4-carboxylate(1.73 g) in ethyl acetate (20 ml.) containing propylene oxide (0.9 ml)at 20°. After the addition was complete the solution was kept for 1hour, then diluted with ethyl acetate and washed with 2 N-hydrochloricacid, sodium bicarbonate solution, water and brine. The dried solutionwas evaporated to give a red foam (2.76 g). The foam (2.6 g) wasdissolved in anisole (5 ml.) and treated with trifluoroacetic acid (20ml.). After 5 minutes the solution was concentrated under reducedpressure and the residue was dissolved in ethyl acetate. The solutionwas washed with water and then extracted with sodium bicarbonatesolution. The combined aqueous extracts were washed with ethyl acetateacidified with 2 N-hydrochloric acid and extracted into ethyl acetate.The combined extracts were washed with brine, dried, concentrated underreduced pressure to a small volume, and added dropwise to stirredpetroleum (ca. 500 ml) to give the title acid as a yellow solid (1.38 g)[α]_(D) -79° (c 1.2 DMSO), λ_(max). (pH 6 buffer) 256 nm (ε19,250),λ_(max). (Nujol) include 3650-2100 (bonded OH), 3250 (NH), 1769(β-lactam), 1660+1525 cm.⁻¹ (CONH), τ (DMSO-d₆) 0.33 (d, J 8 Hz; CONH),2.2-2.7 (m; phenyl protons), 4.12 (dd, J 5 and 8 Hz; C-7H), 4.78 (d, J 5Hz; C-6H), 5.43+5.77 (2 ds, branches of quartet, J 18 Hz; C-3 CH₂),6.17+6.41 (2 ds, branches of quartet, J 18 Hz; C-2 CH₂) and 7.30 (s;CH₃).

EXAMPLES 5-16 General Procedures for the Preparation of7β-(2-Hydroxyimino-2-arylacetamido)-3-(substituted)-methylceph-3-em-4-carboxylicAcids (i) Preparation of the Intermediate 2-Dichloroacetoxyimino Esters

Method A

To a solution of the t-butyl or diphenylmethyl ester of7β-amino-3-(substituted)-methylceph-3-em-4-carboxylic acid (1 equiv.) inethyl acetate was added, dropwise with stirring at room temperature, asolution of the appropriate 2-dichloroacetoxyimino-2-arylacetyl chloride(syn or anti- isomer) (1-1.15 equivs.) in ethyl acetate. The mixture wasstirred for a period of 1-2 hr. during which the hydrochloride of the7β-amino-3-(substituted)methylceph-3-em-4-carboxylic acid esterprecipitated and was removed by filtration. The filtrate was washedsuccessively with 2 N-hydrochloric acid, water, briefly with saturatedsodium hydrogen carbonate solution and brine. The organic layer wasdried and evaporated to give the required 2-dichloroacetoxyimino esteras a foam or oil.

Method B

To a solution of the t-butyl or diphenylmethyl ester of7β-amino-3-(substituted)-methylceph-3-em-4-carboxylic acid (1 equiv.)and propylene oxide (3-15 equivs.) in ethyl acetate (methylene chloridewas used in Example 7) was added, dropwise with stirring at roomtemperature, a solution of the appropriate2-dichloroacetoxyimino-2-arylacetyl chloride (syn-isomer) (1.05-1.25equivs.) in ethyl acetate. Stirring was continued until the reaction wascomplete (t.l.c, usually 40 min.-2hr.) at room temperature. The reactionsolution was then worked up as described in Method A to give therequired ester.

Method C

A solution of the 2-dichloroacetoxyimino-2-arylacetyl chloride(syn-isomer) (1-1.1 equiv.) in ethyl acetate was added dropwise to astirred suspension of the diphenylmethyl7β-amino-3-acyloxy-methylceph-3-em-4-carboxylate p-toluenesulphonic acidsalt (1 equiv.) and propylene oxide (8-20 equiv.) in ethyl acetate atroom temperature. After stirring for 20 minutes - 2 hours the resultingsolution was worked up as described in Method A to give the requiredester.

Method D

As for method C except that the reaction was effected in a mixture ofacetonitrile and dimethylacetamide in place of ethyl acetate-propyleneoxide; this applies only to Example 12.

(ii) Deprotection of the Intermediate Esters

Method E

The t-butyl or diphenylmethyl 2-dichloroacetoxyimino-ester prepared byMethods A or B was dissolved in trifluoroacetic acid (7-15 ml./g. ester)and left at room temperature for 5-10 min. then evaporated under reducedpressure. The crude product was sometimes azeotroped with benzene toremove traces of trifluoracetic acid. The crude product was taken up inethyl acetate and extracted with a saturated solution of sodium hydrogencarbonate. The aqueous extracts were washed with ethyl acetate and thenacidified with 2 N-hydrochloric acid and extracted into ethyl acetate.The organic layer was separated, dried and evaporated to a small volumeand added dropwise to a large, well-stirred, volume of petroleum (b.p.40°-60°). The resulting amorphous solid was collected and dried in vacuoto provide the required7β-(2-hydroxyimino-2-arylacetamido)-3-(substituted)-methylceph-3-em-4-carboxylicacid.

Method F

The ester prepared by Methods A-D was dissolved in anisole (1-15 ml./g.ester) and treated with trifluoroacetic acid (4-10 ml./g. ester) at roomtemperature. After 5-10 mins. the trifluoroacetic acid was removed byevaporation under reduced pressure and the required acid was isolated asdescribed in Method E.

(iii) Preparation of Diphenylmethyl7β-amino-3-acyloxymethylceph-3-em-4-carboxylate toluene-p-sulphonatesalts used as Starting Materials in Examples 11-14 inclusive. (a)Diphenylmethyl3-pivaloyloxymethyl-7β-(thien-2-yl)acetamidoceph-3-em-4-carboxylate

A solution of pyridine (2.4 ml.) in dry tetrahydrofuran (5 ml.) wasadded to a stirred solution of diphenylmethyl3-hydroxymethyl-7β-(thien-2-yl)acetamido-ceph-3-em-4-carboxylate (3.12g) and pivaloyl chloride (7.2 g) in dry tetrahydrofuran (150 ml) at 20°.The solution was stirred at 20° for 16 hours, filtered and concentratedunder reduced pressure. The residue was dissolved in ethyl acetate andwashed successively with sodium bicarbonate solution, 2 N-hydrochloricacid, sodium bicarbonate solution, water and brine. The dried solutionwas concentrated under reduced pressure to give a solid residue that wastriturated with ether to give the title ester (2.7 g; 75%), [α]_(D) +5.1(c 1.4, CHCl₃), λ_(inflex). (ethanol) 235 (ε14,100), 257 (ε8,300) and263 nm. (ε8,050), λ_(max). (CHBr₃) 1787 (β-lactam), 1722 (ester), 1680and 1510 cm.⁻¹ (CONH) τ (CDCl₃) values include 8.81 (singlet; C(CH₃)₃).

Similarly prepared were:

(b) Diphenylmethyl3-benzoyloxymethyl-7β-(thien-2-yl)acetamidoceph-3-em-4-carboxylate

(88%), λ_(max). (EtOH) 223 nm (ε28,600), λ_(inflex). 260 (ε9,800) and278.5 nm (ε7,300), λ_(max). (CHBr₃) 1795 (β-lactam), 1729 (ester), 1690and 1516 cm⁻¹ (CONH) τ (CDCl₃) values include 2.3-3.1 (aromatic protons)6.18 (singlet; thienyl-CH₂) 4.62+5.02 (2 doublets J 14 Hz, C-3 CH₂ OCO).

(c) Diphenylmethyl3-crotonoyloxymethyl-7β-(thien-2-yl)acetamidoceph-3-em-4-carboxylate

(52%), [α]_(D) +7.2° (c 0.8 CHCl₃), λ_(inflex). (ethanol) 237.5 (ε14,400) and 260 nm (ε 8,000), ν_(max). (CHBr₃) 1783 (β-lactam), 1719(ester), 1680 and 1510 cm.⁻¹ (CONH), τ values (CDCl₃) include 6.19(singlet); thienyl-CH₂) and 8.12 (double doublet, J 2 and 7 Hz;CH-CHCH₃).

(d) Diphenylmethyl3-isobutyryloxymethyl-7β-(thien-2-yl)acetamidoceph-3-em-4-carboxylate

(75%), [α]_(D) +4° (c 0.9 CHCl₃), λ_(inflex). (EtOH) 235 (ε 13,400), 257(ε 7,900) and 261.5 nm (ε 7,750), ν_(max). (CHBr₃) 1767 (β-lactam), 1710(ester), 1667 and 1500 cm.⁻¹ (CONH), τ values (CDCl₃) include 6.19(singlet; thienyl CH₂), 8.89 (doublet, J 6.5 Hz; (CH₃)₂ CH).

(e) Diphenylmethyl 7β-amino-3-pivaloyloxymethylceph-3-em-4-carboxylatetoluene-p-sulphonate salt.

A solution of phosphorus pentachloride (6.2 g) in methylene chloride (80ml) was added to a cooled (-10°) and stirred solution of diphenylmethyl3-pivaloyloxymethyl-7β-(thien-2-yl)acetamidoceph-3-em-4-carboxylate (6.0g) and pyridine (9.6 ml.) in methylene chloride (80 ml). After 30 minutemethanol (100 ml.) was added at such a rate that the temperatureremained at -10°. The solution was then allowed to warm to 20° and after3 hours at 20° was cooled to 0°. 2 N-Hydrochloric acid (140 ml.) wasadded to the vigorously stirred solution. After the stirring hadcontinued for 1 hour the methylene chloride layer was separated andwashed successively with 2 N-hydrochloric acid, sodium bicarbonatesolution, water and brine, dried and concentrated under reducedpressure. The residual gum was dissolved in ethyl acetate (10 ml.) andwas treated with a solution of toluene-p-sulphonic acid monohydrate(1.89 g) in ethyl acetate (10 ml.). The cooled solution depositedcrystals that were collected and washed with ethyl acetate and ether togive the title salt (4.34 g; 66%), [α]_(D) +5.9° (c 1, DMSO), λ _(max).(ethanol) 261.5 nm (ε 7,700), λ_(inflex). 267.5 (ε 7,400) and 226.5 nm(ε 16,600), λ_(max). (CHBr₃) 2600-2800 (NH₃ ⁺), 1800 (β-lactam) and 1731cm.⁻¹ (ester), τ values (CDCl₃) include 2.20+2.98 (2 doublets, J 8 Hz;toluene-sulphonate aromatic protons) and 8.89 (singlet; C(CH₃)₃).Similarly prepared were:

(f) Diphenylmethyl 7β-amino-3-benzoyloxymethylceph-3-em-4-carboxylatetoluene-p-sulphonate salt,

as needles; (75%), [α]_(D) +9.5° (c 0.94 DMSO), λ_(max). (ethanol) 221(ε 32,200) and 262 nm (ε 9,100), ν_(max). (Nujol) 2600-2800 (NH₃ ⁺),1804 (β-lactam) and 1730 cm⁻¹ (ester), τ (DMSO-d₆) values include4.79+4.99 [2 doublets, (branches of quartet) J 14 Hz; C-3 CH₂ ] and 7.70(singlet; CH₃).

(g) Diphenylmethyl 7β-amino-3-crotonoyloxymethylceph-3-em-4-carboxylatetoluene-p-sulphonate salt,

(54%), [α]_(D) +7.3° (c 0.89 DMSO), λ_(max). (ethanol) 261.5 nm (ε8,000), λ_(inflex). 266 nm (ε 7,700) ν_(max). (CHBr₃) 2600-2700 (NH₃ ⁺),1790 (β-lactam), 1720 and 1221 cm.⁻¹ (ester), τ values (CDCl₃) include2.20+2.89 [2 doublets, (branches of quartet) J 8 Hz;toluene-p-sulphonate aromatic protons] and 8.11 (double doublet, J 6.5and 1.5 Hz; CH═CH--CH₃).

(h) Diphenylmethyl 7β-amino-3-isobutyryloxymethylceph-3-em-4-carboxylatetoluene-p-sulphonate salt,

(65%), [α]_(D) +5.3° (c 1.21, DMSO), λ_(max). (EtOH) 262 nm (ε 8,000),ν_(max). (CHBr₃) 1780 (β-lactam), 1718 cm.⁻¹ (ester), τ values (CDCl₃)include 2.21, 2.99 (2 doublets J 8 Hz; toluene-p-sulphonate) and 8.91(doublet, J 6 Hz; (CH₃)₂ CH).

EXAMPLE 5 (a) t-Butyl7β-(2-dichloroacetoxyimino-2-phenylacetamido)-3-methylceph-3-em-4-carboxylate(syn-isomer)

as a pale yellow foam (75%), ν_(max). (CHBr₃) 3400 (NH), 1782(β-lactam), 1712 (ester), 1782 and 1693 cm.⁻¹ (CONH), τ (DMSO-d₆) valuesinclude 2.15-2.60 (multiplet; aromatic protons), 3.03 (singlet; CHCl₂),8.03 (singlet; C-3 methyl), 8.54 (singlet; t-butyl ester) was preparedby Method A.

(b) 7β-(2-Hydroxyimino-2-phenylacetamido)-3-methylceph-3-em-4-carboxylicacid (syn-isomer containing ca. 10% of the anti-isomer)

(88%), ν_(max). (Nujol) 3270 (NH), 1760 (β-lactam), 2600 and 1710 (CO₂H), 1670 and 1530 cm⁻¹ (CONH), τ (DMSO-d₆) values include 0.36 (doublet,J 9 Hz; NH of syn-isomer), 1.15 (doublet, J 9 Hz; NH of anti-isomer),2.25-2.65 (multiplet; aromatic protons), 7.92 (singlet; CH₃) wasprepared by Method E.

EXAMPLE 6 (a) Diphenylmethyl7β-(2-dichloroacetoxyimino-2-phenylacetamido)-3-methylthiomethylceph-3-em-4-carboxylate(syn-isomer)

as an oil, ν_(max). (CHBr₃) 3500 (OH), 1790 (β-lactam), 1726 (ester),1696 and 1520 cm.⁻¹ (CONH), τ (DMSO-d₆) 2.1-2.8 (multiplet; aromaticprotons), 3.05 (singlet; diphenylmethyl ester), 4.05 (quartet, J 9 Hz;and 4.5 Hz; C-7 H), 4.85 (doublet, J 4.5 Hz; C-6 H), 6.45 (broadsinglet; C-2 and C-3 CH₂), 8.2 (singlet; SCH₃) was prepared by Method A.

(b)7β-(2-Hydroxyimino-2-phenylacetamido)-3-methylthiomethylceph-3-em-4-carboxylicacid (syn-isomer)

[α]_(D) +47.5° (c 1, DMSO), λ_(max). (pH 6 phosphate buffer) 255 nm (ε18,400), ν_(max). (Nujol) 3270 (NH and OH), 1752 (β-lactam), 1660 and1518 cm.⁻¹ (CONH), τ (DMSO-d₆) 0.35 (doublet, J 9 Hz; NH), 2.3-2.7(multiplet; aromatic protons), 4.15 (quartet, J 9 Hz and 4.5 Hz; C-7 H),4.7 (doublet, J 4.5 Hz; C-6 H), 6.35 (broad singlet; C-2 and C-3 CH₂)7.98 (singlet; S--CH₃) was prepared by Method E.

EXAMPLE 7 (a) Diphenylmethyl7β-(2-dichloroacetoxyimino-2-phenylacetamido)-3-vinylceph-3-em-4-carboxylate(syn-isomer) as a yellow foam ν_(max). (CHBr₃) 3500 (OH), 3380 (NH),1770 (β-lactam), 1720 (ester), 1685 and 1510 cm⁻¹ (CONH), τ (CDCl₃)values include 2.2-2.85 (multiplet; aromatic protons), 4.0-5.0(multiplet; C-6 H, C-7H and vinyl --CH₂), 6.40 (broad singlet; C-2 CH₂)was prepared by Method B. (b)7β-82-Hydroxyimino-2-phenylacetamido)-3-vinylceph-3-em-4-carboxylic acid(syn-isomer)

as a white solid (45%), [α]_(D) -72° (c 0.85, DMSO), λ_(max). (pH 6buffer) 285 nm (ε 16,400), ν_(max). (Nujol) 3270 (NH and OH), 1754(β-lactam), 1710 (CO₂ H), 1660 and 1520 cm⁻¹ (CONH), τ (DMSO-d6) valuesinclude 0.30 (doublet, J 9 Hz; NH), 2.3-2.6 (multiplet; aromaticprotons), 3.03 (quartet, J 11 Hz and 18 Hz; CH═CH₂), 4.37 and 4.66 (twodoublets, J 11 Hz and 18 Hz; CH═CH₂), 6.08 and 6.41 [two doublets(branches of quartet) J 18 Hz; C-2 CH₂ ] was prepared by Method E.

EXAMPLE 8 (a)t-Butyl-3-Acetoxymethyl-7β-[2-dichloroacetoxyimino-2-(thien-2-yl)acetamido]-ceph-3-em-4-carboxylate(syn isomer) was isolated as an oil by Method A and deprotected byMethod F to give: (b) 3-Acetoxymethyl-7β-[2-hydroxyimino-2-(thien-2-yl)acetamido]ceph-3-em-4 -carboxylic acid (syn-isomer)

as an amorphous solid (0.36 g.), [α]_(D) +57° (c 0.8, DMSO), λ_(max).(ethanol) 263 nm (ε 13,900), ν_(max). (Nujol) 3280 (NH), 1772(β-lactam), 1720 (acetate), and 1662 and 1530 cm.⁻¹ (CONH), τ (DMSO-d₆)values include 0.23 (doublet, J 8 Hz; NH), 2.36 (double doublet, J 1 and5 Hz; thienyl C-5 H), 2.82 (multiplet; thienyl C-3 H and C-4H), and 7.93(singlet; OCOCH₃).

EXAMPLE 9 (a) Diphenylmethyl3-azidomethyl-7β-(2-dichloroacetoxyimino-2-phenylacetamido)ceph-3-em-4-carboxylate(syn-isomer)

was obtained as a solid (46%), λ_(max). (EtOH) 254 nm (ε 18,000),ν_(max). (CHBr₃) 3420 (NH), 2128 (N₃), 1800 (β-lactam), τ (CDCl₃) valuesinclude 2.1-2.85 (multiplet; aromatic protons), 3.79 (singlet CHCl₂),using Method B. Deprotection by Method F gave

(b) 3-Azidomethyl-7β-(2-hydroxyimino-2-phenylacetamido)ceph-3-em-4-carboxylic acid (syn-isomer)

(85%), [α]_(D) + 70° (c 0.84, DMSO), λ_(max). (pH 6 phosphate buffer)253.5 nm (ε 18,800), ν_(max). (Nujol) 3260 (NH), 2096 (N₃) 1762(β-lactam), 1650 and 1520 cm.⁻¹ (CONH), τ (DMSO-d6) values include 0.30(NH), 2.3-2.65 (aromatic protons), 5.57 and 6.06 [two doublets, J 13 Hz;C-3 CH₂ ].

EXAMPLE 10 EXAMPLE 10 (a) Diphenylmethyl7β-(2-dichloroacetoxyimino-2-phenylacetamido)-3-methoxymethylceph-3-em-4-carboxylate(syn-isomer)

as a pale yellow foam (2.31 g.; 94%), [α]_(D) +24° (c 0.8 DMSO),λ_(max). (EtOH) 256 nm (ε 17,800), ν_(max). (Nujol) 1790 (β-lactam),1725 (CO₂ R), 1698 and 1520 cm.⁻¹ (amide), τ (DMSO-d6) values include2.40-2.73 (multiplet; aromatic protons), 3.75 (singlet; CHCl₂), 6.80(singlet; --OCH₃) was prepared by Method B and deprotected by Method Fto give:

(b)7β-(2-Hydroxyimino-2-phenylacetamido)-3-methoxymethylceph-3-em-4-carboxylicAcid (syn-isomer)

as a solid (55%), [α]_(D) +77° (c 1.02, DMSO), λ_(max). (EtOH) 253 nm (ε16,800), ν_(max). (Nujol) 1785 (β-lactam), 1730 (--CO₂ H), 1678 and 1580cm.⁻¹ (amide), τ (DMSO-d6) values include 0.35 (doublet J 9 Hz; NH), 2.3to 2.6 (multiplet; aromatic protons), 4.14 (quartet J 9 Hz and 4.5 Hz;C-7 H), 4.79 (doublet J 4.5 Hz; C-6H), 6.80 (singlet; OCH₃).

EXAMPLE 11 (a) Diphenylmethyl 7β-(2-dichloroacetoxyimino-2phenylacetamido)-3-pivaloyloxymethylceph-3-em-4-carboxylate (syn-isomer)

was obtained as an oil by Method C and directly deprotected by Method Fto give

(b)7β-(2-Hydroxyimino-2-phenylacetamido)-3-pivaloyloxymethylceph-3-em-4-carboxylicacid (syn isomer)

as a yellow solid (74%), [α]_(D) +62° (c 1, DMSO), λ_(max). (pH 6phosphate) 253.5 nm (ε17,200), ν_(max). (Nujol) 3700-2200 (bonded OH),1771 (β-lactam), 1710 (ester and carboxylic acid), 1665 and 1526 cm.⁻¹(CONH), τ (DMSO-d₆) values include 0.34 (doublet, J 8 Hz; NH) 2.3-2.65(multiplet; aromatic protons), and 8.82 (singlet; C(CH₃)₃).

EXAMPLE 12 (a) Diphenylmethyl3-benzoyloxymethyl-7β-(2-dichloroacetoxyimino-2-phenylacetamido)ceph-3-em-4-carboxylate

was isolated as a mixture of syn and anti-isomers prepared by Method D.Deprotection of the mixture by Method F and separation of the acids bypreparative layer chromatography on Merck silica gel 254F plates usingchloroform:methanol:acetic acid (90:7:5 by volume) gave, as the slowermoving component:

(b)3-Benzoyloxymethyl-7β-(2-hydroxyimino-2-phenylacetamido)ceph-3-em-4-carboxylicacid (syn-isomer)

[α]_(D) +54.4° (c 1, DMSO), λ_(max). (pH 6 phosphate) 236.5 nm(ε22,200), λ_(inflex). 250 nm (ε19,600), ν_(max). (Nujol) 3680-2200(bonded OH), 1770 (β-lactam), 1710 (carboxylic acid and ester), 1680 and1515 cm⁻¹ (CONH), τ (DMSO-d₆) values include 0.32 (doublet, J 8 Hz; NH)2.00-2.50 (multiplet; aromatic protons), and 6.16 and 6.38 [2 doublets(branches of quartet) J 18 Hz; C-2 CH₂ ].

EXAMPLE 133-Crotonoyloxymethy-7-β-(2-hydroxyimino-2-phenylacetamido)ceph-3-em-4-carboxylicacid (syn-isomer)

as an amorphous solid (60%), [α]_(D) +54° (c 1.0, DMSO), λ_(max). (pH 6phosphate) 252 nm (ε16,700), ν_(max). (Nujol) 1774 (β-lactam), 1710 (CO₂H), 1670 and 1530 cm⁻¹ (CONH), τ (DMSO-d₆) values include 0.35 (doublet,J 8 Hz; NH) 2.3 to 2.7 (multiplet; aromatic protons), 3.03 (doublequartet, J 15 and 7 Hz; CH═CH--CH₃), 4.09 (doublet J 15 and 1 Hz;CH═CH--CH₃), 8.14 (double doublet, J 7 and 1 Hz; CH═CH--CH₃) wasprepared by a combination of Methods C and F, the intermediate esterbeing used without characterisation.

EXAMPLE 14 (a) Diphenylmethyl7β-(2-dichloroacetoxyimino-2-phenylacetamido)-3-isobutyryloxymethylceph-3-em-4-carboxylate(syn isomer) was isolated as a gum [α]_(D) +14° (c 1, DMSO), λ_(max).(EtOH) 255 nm (ε12,300), ν_(max). (CHBr₃) 3380 (NH), 1790 (β-lactam),1695 and 1518 cm. ⁻¹ (CONH), τ (CDCl₃) values include 2.0-2.9(multiplet; NH and aromatic protons), 3.74 (singlet; CHCl₂), 8.88(doublet J 7 Hz; gem dimethyl) using Method C. Deprotection by Method Fgave (b)7β-(2-Hydroxyimino-2-phenylacetamido)-3-isobutyryloxymethylceph-3-em-4-carboxylicacid (syn-isomer) as a solid (87%), [α]_(D) +52° (c 1.0, DMSO), λ_(max).(EtOH) 253 nm (ε14,100), ε_(max). (Nujol) 3280 (NH), 1770 (β-lactam),1660 and 1520 cm.⁻¹ (amide), τ (DMSO-d6) values include 0.33 (doublet J9 Hz; NH), 2.3-2.6 (multiplet; aromatic protons) and 8.86 (doublet J 7Hz; C(CH₃)₂). EXAMPLE 15 (a) t-Butyl3-acetoxymethyl-7β-[2-(4-chlorophenyl)-2-dichloroacetoxyimino-acetamido]-ceph-3em-4-carboxylate(syn-isomer)

was isolated as a yellow foam by Method B and was deprotected by MethodF to give:

(b)3-Acetoxymethyl-7β-[2-(4-chlorophenyl)-2-hydroxyimino-acetamido]-ceph-3-em-4-carboxylicacid (syn isomer)

as a solid (16% overall yield based on 7β-amino-ester), [α]_(D) +62° (c1.0 DMSO), λ_(max). (pH 6 buffer) 258 nm (ε20,900), ν_(max). (Nujol)3280 (NH), 1770 (β-lactam), 1660 and 1524 cm.⁻¹ (CONH), τ (DMSO-d6)values include 0.33 (doublet J 9 Hz; NH) and 7.98 (singlet; OCOCH₃).

EXAMPLE 16 (a) t-Butyl3-acetoxymethyl-7β-(2-dichloroacetoxyimino-2-naphth-1'-ylacetamido)ceph-3-em-4-carboxylate(syn-isomer)

was isolated as a solid (70%), [α]_(D) +32° (c 0.75, DMSO), λ_(max).(EtOH) 270 nm (ε 13,050), ν_(max). (CHBr₃) 3540 (OH), 3380 (NH), 1784(β-lactam), 1738 cm. (OCOCH₃), τ (CHCl₃) values include 3.68 (singlet;CHCl₂), 7.93 (singlet; OCOCH₃), 8.46 (singlet; C(CH₃)₃) by Method B.Deprotection by Method F gave:

(b)3-Acetoxymethyl-7β-(2-hydroxyimino-2-naphth-1'-ylacetamido)ceph-3-em-4-carboxylicacid (syn-isomer) (97%), [α]_(D) +44° (c 0.72, DMSO), λ_(max). (pH 6phosphate buffer) 260 nm (ε 11,850), ν_(max). (Nujol) 1770 (β-lactam),1714 cm.⁻¹ (OCOCH₃), τ (DMSO-d6) values include 0.22 (doublet; J 9 Hz;NH), 1.3-2.5 (multiplet; aromatic protons), 7.94 (singlet; OCOCH₃).EXAMPLE 177β-[2-Hydroxyimino-2-(thien-2-yl)acetamido]-3-(5-methyl-1,3,4-thiadiazol-2-yl)thiomethylceph-3-em-4-carboxylicacid (syn-isomer)

A solution of 2-dichloroacetoxyimino-2-(thien-2-yl)acetyl chloride 0.585g.) in ethyl acetate (5 ml.) was added to a stirred suspension ofdiphenylmethyl7β-amino-3-(5-methyl-1,3,4-thiadiazol-2-yl)thiomethylceph-3-em-4-carboxylate(1 g.) in ethyl acetate (10 ml.) and propylene oxide (1 ml.) at 20°.After 30 minutes all the solid had dissolved. The solution was washedwith 2 N-hydrochloric acid, saturated sodium bicarbonate solution, waterand brine, dried and concentrated to give crude diphenylmethyl7β-[2-dichloroacetoxyimino-2-(thien-2-yl)acetamido]-3-(5-methyl-1,3,4-thiadiazol-2-yl)thiomethylceph-3-em-4-carboxylate(syn-isomer) as a solvated foam (1.567 g.) λ_(max). (EtOH) 267.5 nm (E₁¹ 240), τ values (CDCl₃) include 3.00 (singlet, --CHPh₂), 3.75 (singlet;CHCl₂) and 7.35 (singlet; CH₃).

Trifluoroacetic acid (8 ml.) was added to a solution of the above ester(1.387 g.) in anisole (2 ml.) at 20°. After 5 minutes the solution wasconcentrated under reduced pressure and the residue was dissolved inethyl acetate. The solvent was evaporated and again the residue wasdissolved in ethyl acetate. The solution was washed with water and thenextracted with sodium bicarbonate solution. The combined extracts werewashed with ethyl acetate, then taken to pH 1.9 with concentratedhydrochloric acid and extracted with ethyl acetate. The extract waswashed with water and brine, dried and concentrated under reducedpressure to give a foam. Trituration with ether gave the title compoundas a buff solid (0.50 g.), [α]_(D) -84° (c 1, DMSO), λ_(max). (pH 6buffer) 271.5 nm (ε 17,600), ν_(max). (Nujol) include 3250 (NH), 1780(β-lactam), 2600+1710 (CO₂ H), and 1674+1548 cm.⁻¹ (CONH), τ values(DMSO-d₆) 0.24 (doublet, J 8 Hz; NH) 2.37 and 2.82 (thienyl protons)4.12 (double doublet, J 5 and 8 Hz; C-7H), 4.76 (doublet, J 5 Hz; C-6H),5.40 and 5.75 (2 doublets, branches of quartet, J 13 Hz; C-3 CH₂),6.13+6.40 (2 doublets, branches of quartet, J 18 Hz; C-2 CH₂) and 7.29(singlet; CH₃).

EXAMPLE 18 3-Acetoxymethyl-7β-(2-hydroxyimino-2-phenylacetamio)ceph-3-em-4-carboxylic acid (syn-isomer)

To a stirred solution of 3-acetoxymethyl-7β-aminoceph-3-em-4-carboxylicacid (2.72 g.) and sodium bicarbonate (1.85 g.) in water (50 ml.) andacetone (50 ml.) was added, dropwise with stirring at 5°, a solution of2-dichloroacetoxyimino-2-phenylacetyl chloride (syn-isomer) in acetone(5 ml.) over a period of five minutes. The reaction was stirred for anhour at room temperature, after which the pH was 4.0. The acetone wasremoved under reduced pressure and the mixture was extracted with ethylacetate. The extracts were washed with 2 N-hydrochloric acid andsaturated brine, dried and concentrated to ca. 5 ml. The solution wascooled to -30° for fifteen minutes, filtered and the solid washed withcold ethyl acetate then petroleum spirit (b.p. 40°-60°) and dried togive the title acid as an ethyl acetate solvate (1.2 g; 23%), [α]_(D)+64°, λ_(max). (EtOH) 253 nm (ε 18,400), ν_(max). (Nujol) 3260 (NH),1760 (β-lactam), 1710 (acetate), 1650 and 1550 cm.⁻¹ (amide), τ(DMSO-d6) values include 0.33 (doublet J 9 Hz; NH), 2.3-2.65 (multiplet;aromatic protons), 7.96 (singlet; CH₃ CO).

EXAMPLE 193-Acetoxymethyl-7β-(2-hydroxyimino-2-phenylacetamido)ceph-3-em-4-carboxylicacid (syn isomer)

To a suspension of 3-acetoxymethyl-7-aminoceph-3-em-4-carboxylic acidp-toluenesulphonic acid salt (4.8 g) in acetonitrile:dimethylacetamide(6:1, 25 ml.) was added dropwise with stirring at room temperature a 3 Msolution of 2-dichloroacetoxyimino-2-phenylacetyl chloride (syn isomer)in acetonitrile (5 ml.). The reaction was stirred at room temperatureuntil the solution was homogeneous, then poured into saturated aqueoussodium bicarbonate solution. The solution was washed with ethyl acetate,acidified to pH 1.0 (2 N-hydrochloric acid) and extracted with ethylacetate. The combined extracts were washed with water, dried andconcentrated to ca. 10 ml. The concentrate was added dropwise topetroleum spirit (b.p. 40°-60°) with vigorous stirring. This produced agummy solid which was stirred with ethyl acetate (50 ml.) and thesolution filtered and added dropwise to petroleum spirit (300 ml.). Theprecipitated solid was filtered and dried to give the title acid (1.47g; 29%), [α]_(D) +57° (c 0.7 DMSO) λ_(max). (EtOH) 253.5 nm (ε 15,800).

EXAMPLE 207β-(2-Hydroxyimino-2-phenylacetamido)-3-methylceph-3-em-4-carboxylicacid (syn-isomer)

A solution of hydroxylamine hydrochloride (34.8 mg.) in dry methanol (5ml.) was neutralised to phenolphthalein with sodium methoxide inmethanol. This solution was added to a solution oft-butyl-7β-phenylglyoxamido-3-methylceph-3-em-4-carboxylate (201 mg.) indry methanol (10 ml.) and the mixture was stirred for 2 days at roomtemperature. The residue obtained by evaporation was dissolved in ethylacetate (20 ml.) and the solution was washed with water, dried andevaporated to give a yellow froth (220 mg.). Preparative chromatographyon silica plates developed with 20% v/v ethyl acetate in benzene led toisolation of the starting material (46 mg.),t-butyl-7β-(2-hydroxyimino-2-phenylacetamido)-3-methylceph-3-em-4-carboxylate(syn-isomer) (22 mg.) and a slow-running fraction (94 mg.) which did notcontain a β-lactam ring. The required ester (20 mg.) was shaken withtrifluoroacetic acid (1 ml.) at room temperature for 10 min. and thenevaporated to give the title acid (15 mg.) which was identified with anauthentic sample by thin layer chromatography and n.m.r. spectrum [τ(DMSO-d₆) includes 0.38 (doublet, J=8 Hz, NH of syn-isomer), 2.25-2.65(multiplet; phenyl protons) and 7.95 (singlet; CH₃)].

The starting ester was prepared as follows: phenylglyoxylyl chloride(0.37 g.) was added to a solution of t-butyl7β-amino-3-methylceph-3-em-4-carboxylate (0.54 g.) in ethyl acetate (10ml.) and the solution was stirred at room temperature for 1.5 hr. whenno starting material remained (t.l.c.). The reaction mixture was dilutedwith ethyl acetate and washed successively with saturated sodiumhydrogen carbonate solution, water and brine. Evaporation of the driedorganic layer gave an oil that slowly crystallised (0.80 g).Recrystallisation from cyclohexane gave t-butyl7β-phenylglyoxamido-3-methylceph-3-em-4-carboxylate (0.49 g, 62%), m.p.141°-143°, [α]_(D) +122° (c 1, ethanol), ν_(max). (CHBr₃) 1781 cm.⁻¹(β-lactam), τ (CDCl₃) values include 1.5-1.75 (ortho aromatic protons),2.0-2.7 (aromatic protons) 7.89 (singlet; CH₃), 8.45 (singlet; t-butyl).

EXAMPLE 21N-[7β-(2-Hydroxyimino-2-phenylacetamido)-ceph-3-em-3-yl-methyl]-(4-carbamoylpyridinium)-4-carboxylate(syn-isomer)

A solution of3-acetoxymethyl-7β-(2-hydroxyimino-2-phenylacetamido)-ceph-3-em-4-carboxylicacid (syn-isomer) (500 mg) and isonicotinamide (500 mg) in water (10ml.) was heated at 70° for 1.5 hours. The solution was diluted withwater, filtered to remove a small amount of dark insoluble material, andpassed down a column of Bio-rad AG-1-X8 ion exchange resin (acetateform). The eluate was examined by electrophoresis at pH 1.9, whichrevealed that two components were present, both of which migratedtowards the cathode. The faster moving component corresponded toisonicotinamide, the slower had a mobility similar to cephaloridine, andgave the expected purple colouration with iodoplatinate reagent.Evaporation of the eluate under reduced pressure at 35° gave a residuewhich was triturated with acetone and filtered. The solid was washedwith acetone and dried, giving 140 mg. (25%) of the title compound. Thematerial was homogeneous on electrophoresis at pH 1.9, and migratedtowards the cathode. [α]_(D) -44°(c 0.72, DMSO), λ_(max). (EtOH) 251 nm(ε 13,000), ν_(max). (Nujol) 3330, 3150 (NH and OH), 1771 (β-lactam),1680 and 1560 (CONH) and 1606 cm.⁻¹ (CO₂ --), τ (DMSO-d₆) values include0.37, 1.50 [two doublets (branches of a quartet), J 7 Hz;p-disubstituted pyridine ring], 1.15 and 1.76 (two broad singlets;CONH₂), 2.3-2.7 (multiplet; aromatic protons), 4.26 (multiplet; C-7 Hand C-3 CH₂), 4.8 (multiplet; C-6 H and C-3 CH₂), 6.40 and 6.88 [twodoublets (branches of a quartet), J 18 Hz; C-2 CH₂ [.

EXAMPLE 22N-[7β-(2-Hydroxyimino-2-phenylacetamido)-ceph-3-em-3-ylmethyl]-pyridinium-4-carboxylate(syn-isomer)

A solution of3-acetoxymethyl-7β-(2-hydroxyimino-2-phenylacetamido)ceph-3-em-4-carboxylicacid (syn-isomer) (5.0 g) and pyridine (4 ml.) in water (100 ml.) washeated at 70° for 3 hours under an atmosphere of nitrogen. The reactionmixture was cooled and passed down a column of AG-1-X8 resin (acetateform) eluting with water. Fractions of 100 ml. were collected and thoseshown by electrophoresis to contain the required product were combinedand lyophilised to giveN-[7β-(2-hydroxyimino-2-phenylacetamido)ceph-3-em-3ylmethyl]pyridinium-4-carboxylate(syn-isomer) (0.75 g., 14%), [α]_(D) -49.5° (c 0.83, DMSO), λ_(max). (pH6 phosphate buffer) 255 nm (ε 20,500), ν_(max). (Nujol) 1770 (β-lactam),1660 and 1550 cm.⁻¹ (CONH), τ (DMSO-d₆) values include 0.46, 1.36 and1.80 (pyridine ring protons), 2.3-2.7 (multiplet; aromatic protons).

EXAMPLE 23 (a) Diphenylmethyl7β-(2-dichloroacetoxyimino-2-phenylacetamido)-3-(4,5-dimethoxycarbonyl-1,2,3-triazol-1-yl)-methylceph-3-em-4-carboxylate(syn-isomer)

To a solution of diphenylmethyl3-azidomethyl-7β-(2-dichloroacetoxyimino-2-phenylacetamido)ceph-3-em-4-carboxylate(1.0 g.) in dioxan (40 ml.) was added dimethyl acetylenedicarboxylate(2.5 g.) and the solution was heated under reflux for four hours. Thereaction was cooled, the solvent removed under reduced pressure and theresidue triturated with petroleum spirit (b.p. 40°-60°). The resultingsolid was collected, washed well with petroleum spirit and dried, togive the title ester. (1.2 g; 98%), [α]_(D) +25° (c 1.1, DMSO), λ_(max).(EtOH) 250.5 nm. (ε 19,900), ν_(max). (Nujol) 3380 (NH), 1790(β-lactam), 1690 and 1515 cm.⁻¹ (CONH), τ (CDCl₃) values include2.4-2.75 (multiplet; aromatic protons) 6.09, 6.21 (two singlets; methylesters).

(b)3-(4,5-Dimethoxycarbonyl-1,2,3-triazol-1-yl)methyl-7β-(2-hydroxyimino-2-phenylacetamido)ceph-3-em-4-carboxylicacid (syn-isomer)

To a solution of the above ester (1.0 g.) in anisole (8 ml.) was addedtrifluoroacetic acid (4 ml.). After standing for ten minutes at roomtemperature, the reaction mixture was evaporated to dryness, and benzeneazeotroped from the residue which was then dissolved in ethyl acetate,extracted with sodium bicarbonate solution and the combined extractswere washed with ethyl acetate, acidified and extracted into ethylacetate. The combined organic extracts were dried and concentrated toca. 10 ml. The concentrate was added dropwise with stirring to petroleum(b.p. 40°-60°) and the resulting precipitate filtered and dried to givethe title acid 0.5 g; 75%), [α]_(D) +68° (c 0.7, DMSO), λ_(max). (pH 6phosphate buffer) 249 nm. (ε 22,200), ν_(max). (Nujol) 1790 (β-lactam),1680 and 1540 cm.⁻¹ (amide), τ DMSO-d₆) values include 0.31 (doublet J 8Hz; NH), 2.3-2.7 (multiplet; aromatic protons), 4.21 and 4.48 (twodoublets, J 15 Hz; C-3 CH₂), 6.07 and 6.12 (singlets, methyl esters).

EXAMPLE 247β-(2-Hydroxyimino-2-phenylacetamido)-3-hydroxymethylceph-3-em-4-carboxylicacid sodium salt (syn-isomer)

To3-acetoxymethyl-7β-(2-hydroxyimino-2-phenylacetamido)ceph-3-em-4-carboxylicacid (syn-isomer) (5.0 g) was added sufficient saturated sodiumbicarbonate solution to bring the pH to 7.0, during which time solutionoccurred. To this solution was added water (300 ml.) and defatted wheatgerm (35 g.), and the suspension stirred vigorously whilst the pH wasmaintained at between 6.7 and 6.9 by frequent additions of 2 N-sodiumhydroxide. After addition of ca. 6 ml, the pH remained constant at 6.9.The mixture was poured into acetone (400 ml.), filtered (kieselguhr),and the filtrate evaporated under reduced pressure to remove acetone,then refiltered (kieselguhr). The filtrate was washed with ethylacetate, and the pH adjusted to 2.8. The aqueous phase was extractedwith ethyl acetate, and the extracts were stirred with water (ca. 300ml.) and the pH brought up to 7.0 with 2 N sodium hydroxide. Th phaseswere separated and the aqueous phase washed twice with ethyl acetate,once with ether, evaporated under reduced pressure to remove residualsolvents, and freeze-dried. This gave the title acid (1.5 g: 31%),[α]_(D) +93° (c 1.0, DMSO), λ_(max). (pH 6 phosphate buffer) 252 nm (ε12,800), ν_(max). (Nujol) 1750 (β-lactam), 1650 and 1530 cm.⁻¹ (amide),τ (DMSO-d₆) values include 2.3 to 2.6 (multiplet; aromatic protons),5.72 and 6.05 [two doublets (branches of a quartet), J 13 Hz; CH₂ OH],6.44 and 6.68 [two doublets (branches of a quartet), J 18 Hz; C-2CH₂ ].

EXAMPLE 25 Sodium7β-[2-hydroxyimino-2-(thien-2-yl)acetamiod]3-hydroxymethyl-ceph-3-em-4-carboxylatesyn-isomer).

A solution of sodium3-acetoxymethyl-7β-[2-hydroxyimino-2-(thien-2-yl)acetamido]ceph-3-em-4-carboxylate(syn-isomer) (2.0 g) in water (160 ml.) was warmed to 37° and defattedwheat germ (15 g.) was added. The mixture was stirred at 37° for 4hours, the pH being kept between 6.5 and 6.9 by the addition of 2 Nsodium hydroxide solution (total 2.3 ml.). The mixture was poured intoacetone (200 ml.) and then filtered through kieselguhr. Acetone wasremoved under reduced pressure and the aqueous solution was againfiltered through kieselguhr, washed with ethyl acetate, then coveredwith ethyl acetate and taken to pH 2.7 by the careful addition ofconcentrated hydrochloric acid. The layers were separated and theaqueous layer was re-extracted with ethyl acetate. The combined extractswere washed with water and the pH was taken to 7.0 by the addition of 2N-sodium hydroxide. The organic layer was further extracted with waterand the combined aqueous solution was washed with ethyl acetate andether, degassed and lyophilised to give the title oxime as a brown solid(1.43 g; 79%), [α]_(D) +76° (c 0.46, DMSO), λ_(max). (pH 6 phosphate)261.5 nm (ε 10,600), λ_(inflex). 284 nm (ε 6,500), ν_(max). (Nujol) 1760(β-lactam), 1560 (CO₂ ⁻), 1650 and 1520 cm⁻¹ (CONH), τ (D₂ O) valuesinclude 2.41, 2.63 and 2.83 (doublet, doublet and triplet respectively,J 4 Hz; thienyl protons)

EXAMPLE 26 (a)7β.(2-Acetoxyimino-2-phenylacetamido)-3-acetoxymethylceph-3-em-4-carboxylicacid

To a solution of acetyl chloride (8 ml.) in methylene chloride (8 ml.)was added3-acetoxymethyl-7β-(2-hydroxyimino-2-phenylacetamido)-ceph-3-em-4-carboxylicacid (syn-isomer) (500 mg.) in portions over ten minutes with vigorousstirring at room temperature. A gum formed, and ethyl acetate (8 ml.)was added to achieve solution. After stirring for two hours at roomtemperature, the mixture was added slowly to petroleum spirit (300 ml.)with vigorous stirring. The precipitate was filtered off, washedthoroughly with petroleum spirit, dissolved in chloroform (10 ml.)stirred with activated charcoal and filtered. The filtrate was addeddropwise to petroleum spirit (250 ml.) with stirring. The precipitatewas filtered off and dried giving the title acid, (350 mg; 62%), τ(DMSO-d₆) values include -0.11 (doublet, J 8 Hz; NH), 2.2-2.6(multiplet; aromatic protons), 7.76 (singlet; CH₃.CO₂ N--), 7.94(singlet; CH₃ CO). Signals at τ 0.05 (doublet; J 9 Hz; NH) and 7.78(singlet; CH₃ CO₂ N--) indicated the presence of about 30% of theanti-isomer.

(b)7β-(2-Acetoxyimino-2-phenylacetamido)-3-acetoxymethylceph-3-em-4-carboxylicacid (syn-isomer)

To a solution of pyridine (1.5 ml.) in ethyl acetate (20 ml.) was added3-acetoxymethyl-7β-(2-hydroxyimino-2-phenylacetamido)ceph-3-em-4-carboxylicacid (syn-isomer) (0.5 g.) and the stirred mixture was treated dropwisewith a solution of acetyl chloride (1.0 ml.) in ethyl acetate (5 ml.)and stirring continued for ten minutes. The mixture was poured intowater, the ethyl acetate phase separated and washed with 2N-hydrochloric acid, water, and extracted with saturated aqueous sodiumbicarbonate. The combined aqueous extracts were acidified and extractedwith ethyl acetate and the extracts were dried and concentrated to ca. 5ml. The concentrate was added dropwise with stirring to petroleum (250ml.). The precipitated solid was collected and dried, giving the titleacid (0.32 g; 58%), [α]_(D) +83° (c C.8, DMSO), λ_(max). (pH 6 buffer)258 nm (ε 20,800), ν_(max). (Nujol) 3270 (NH), 1780 (β-lactam), 1680 and1546 cm.⁻¹ (CONH), τ (DMSO-d₆) values include -0.10 (doublet J 8 Hz;NH), 2.2 to 2.6 (multiplet; aromatic protons), 7.78 (singlet;--N.O.COCH₃), 7.94 (singlet; OCOCH₃).

EXAMPLE 273-Acetoxymethyl-7β-(2-chloroacetoxyimino-2-phenylacetamido)-ceph-3-em-4-carboxylicacid (syn-isomer)

To a solution of chloroacetyl chloride (7 ml.) in ethyl acetate (7 ml.)was added portionwise with stirring3-acetoxymethyl-7β-(2-hydroxyimino-2-phenylacetamido)-ceph-3-em-4-carboxylicacid (syn-isomer) (0.488 g.) and the resulting solution was allowed tostand at room temperature for two hours. It was then poured intopetroleum (b.p. 40°-60°; 300 ml.) with vigorous stirring. The resultingsolid was washed several times with petroleum ether, filtered, washedagain with petroleum ether and dried to give the title acid as a yellowsolid (0.453 g; 79%), [α]_(D) +52° (c 0.87, DMSO), λ_(max). (pH 6phosphate buffer) 254 nm (ε 16,700), ν_(max). (CHBr₃) 3421 (NH), 17°1(β-lactam), 1699 and 1521 cm.⁻¹ (CONH), τ (DMSO-d₆) values include -0.13(doublet, J 8 Hz, NH), 5.36 (singlet; CH₂ Cl), 7.96 (singlet; OCOCH₃)

EXAMPLE 283-Acetoxymethyl-7β-(2-ethoxycarbonyloxyimino-2-phenylacetamido)-ceph-3-em-4-carboxylicacid (syn-isomer)

A solution of3-acetoxymethyl-7β-(2-hydroxyimino-2-phenylacetomido)ceph-3-em-4-carboxylicacid (syn-isomer) (0.5 g.) in saturated sodium bicarbonate solution (20ml.) was shaken briefly with a solution of ethyl chloroformate (1 ml.)in ethyl acetate (10 ml.). The aqueous layer was separated and shakenwith a second solution of ethyl chloroformate (1 ml.) in ethyl acetate(10 ml), then separated, washed twice with ethyl acetate, acidified andextracted with ethyl acetate. The combined aqueous extracts were driedand concentrated to ca. 5 ml. The concentrate was added dropwise withstirring to petroleum (200 ml.). The precipitate was filtered and driedto give the title acid (0.45 g., 77%), [α]_(D) +48° (c 0.8, DMSO),λ_(max). (pH 6 phosphate buffer (258 nm (ε 21,800), ν_(max). (Nujol)3270 (NH), 1776 (β-lactam), 1679 and 1535 cm.⁻¹ (CONH), τ (DMSO-d₆)values include -0.13 (doublet, J 8 Hz; NH), 2.2 to 2.5 (multiplet;aromatic protons). 5.68 (quartet, J 8 Hz; OCH₂ CH₃), 7.96 (singlet;OCOCH₃), 8.70 (triplet; J 8 Hz; OCH₂ CH₃).

EXAMPLE 29 (a) Diphenylmethyl3-acetoxymethyl-7β-(2-benzoyloxyimino-2-phenylacetamido)-ceph-3-em-4-carboxylate(syn-isomer)

To a solution of diphenylmethyl3-acetoxymethyl-7β-(2-hydroxyimino-2-phenylacetamido)ceph-3-em-4-carboxylate(1.0 g) and pyridine (1.5 ml.) in ethyl acetate (30 ml.) was addedbenzoyl chloride (1.5 ml.) and the mixture allowed to stand for one hourat room temperature. The solution was then washed with 2 N-hydrochloricacid (50 ml.) and saturated brine, dried (sodium sulphate) andconcentrated to ca. 5 ml. The concentrate was added dropwise topetroleum (b.p. 40°-60°; 350 ml.) and the precipitated solid filtered,washed with petroleum and dried, yielding the title ester as a yellowsolid (1.0 g; 85%), [α]_(D) +6.4° (c 0.94, DMSO), λ_(max). (EtOH) 259 nm(ε 26,700), ν_(max). (CHBr₃) 1780 (β-lactam), 1640 and 1522 cm.⁻¹(CONH), τ (DMSO-d₆) values include -0.27 (doublet J 8 Hz; NH), 1.8-2.8(multiplet; aromatic protens), 8.01 (singlet; OCOCH₃) .

(b)3-Acetoxymethyl-7β-(2-benzoyloxyimino-2-phenylacetamido)ceph-3-em-4-carboxylicacid (syn-isomer)

A solution of diphenylmethyl3-acetoxymethyl-7β-(2-benzoyloxyimino-2-phenylacetamido)ceph-3-em-4-carboxylate(syn-isomer) (0.85 g) in trifluoroacetic acid (10 ml.) and anisole (10drops) was allowed to stand for ten minutes at room temperature, thenevaporated to dryness under reduced pressure. The residue was dissolvedin ethyl acetate and extracted with sodium bicarbonate. The combinedextracts were acidified (2 N-hydrochloric acid) and extracted with ethylacetate. The combined organic extracts were washed with brine, dried,concentrated to ca. 10 ml.; and added dropwise with stirring topetroleum. The precipitated solid was filtered and dried to give thetitle acid (0.39 g; 60%), [α]_(D) +31° (c 0.94 DMSO), λ_(max). (EtOH)260 nm (ε 26,000), ν_(max). (Nujol) 3270 (NH), 1784 cm.⁻¹ (β-lactam), τ(DMSO-d₆) values include -0.27 (doublet J 8 Hz; NH), 1.75-2.6(multiplet; aromatic protons) 7.96 (singlet; OCOCH₃).

The starting material used in (a) above was prepared as follows:

To a solution of3-acetoxymethyl-7β-(2-hydroxyimino-2-phenylacetamido)ceph-3-em-4-carboxylicacid (syn-isomer)(2.0 g) in tetrahydrofuran (50 ml.) maintained at 37°was added portionwise a solution of diphenyldiazomethane in petroleum(b.p. 60°-80°) until the purple colour persisted for one hour. Afteraddition of acetic acid to destroy excess diphenyldiazomethane, thesolution was evaporated to dryness, taken up in ethyl acetate, thenwashed with sodium bicarbonate, and brine, dried and evaporated. Theresidue was triturated with petroleum spirit, and the resulting solidfiltered and dried to give diphenylmethyl3-acetoxymethyl-7β-(2-hydroxyimino-2-phenylacetamido)ceph-3-em-4-carboxylate(syn-isomer) (1.93 g 69%), [α]_(D) +24° (c 1, DMSO), λ_(max). (EtOH) 253nm (ε 16,150), ν_(max). (CHBr₃) 3610 (OH), 1796 cm.⁻¹ (β-lactam), τ(DMSO-d₆) values include 0.27 (doublet, J 9 Hz; NH), 8.03 (singlet;OCOCH.sub. 3).

EXAMPLE 30 (a) Diphenylmethyl3-acetoxymethyl-7β-[2-(4-nitrobenzoyloxyimino]-2-phenylacetamido)ceph-3-em-4-carboxylate(syn-isomer)

To a solution of diphenylmethyl3-acetoxymethyl-7β-(2-hydroxyimino-2-phenylacetamido)ceph-3-em-4-carboxylate(syn-isomer) (1.5 g.) and pyridine (0.5 ml.) in ethylacetate (100 ml.)was added 4-nitrobenzoyl chloride (0.42 g) and the resulting solutionwas stirred at room temperature for one hour. Further portions (0.042 g0.015 g and 0.20 g.) of the acid chloride were added, and the reactionstirred for a total of 4 hours at room temperature. Then the solutionwas washed with 2 N-hydrochloric acid and brine, dried, concentrated toca. 5 ml. and added dropwise with stirring to petroleum spirit (b.p.40°-60°). This gave a solid which was filtered and dried, yielding thetitle ester (1.1 g; 58%), λ_(max). (EtOH) 263 nm (ε 29,000), ν_(max).(CHBr₃) 3400 (NH), 1780 (β-lactam), 1395 and 1525 (NO₂), 1687 and 1515cm.⁻ 1 (CONH), τ (CDCl₃) values include 1.70 and 2.71 (two doublets, J 8Hz; ##STR33## 2.1-2.85 (multiplet; aromatic protons), 8.03 (singlet;OCOCH₃)

(b)3-Acetoxymethyl-7β-[2-(4-nitrobenzoyloxyimino)-2-phenylacetamido]-ceph-3-em-4-carboxylicacid (syn-isomer)

A solution of diphenylmethyl3-acetoxymethyl-7β-[2-(4-nitrobenzoyloxyimino)-2-phenylacetamido]ceph-3-em-4-carboxylate(syn-isomer) (1.0 g) in trifluoroacetic acid (10 ml.) was allowed tostand at room temperature for ten minutes. After evaporation oftrifluoroacetic acid under reduced pressure, the residue was dissolvedin ethyl acetate and extracted with saturated aqueous sodiumbicarbonate. A solid precipitated during the bicarbonate extraction andwas collected, washed with water and ethyl acetate, and partitionedbetween ethyl acetate and 2 -N-hydrochloric acid. The phases wereseparated and the upper layer was washed with water, dried, concentratedto ca. 10 ml. and added dropwise with stirring to petroleum (b.p.40°-60°; 200 ml.). The precipitated solid was filtered and dried to give3-acetoxymethyl-7β-[2-(4-nitrobenzoyloxyimino)-2-phenylacetamido]ceph-3-em-4-carboxylicacid (syn-isomer) (0.150 g; 20%), [α]_(D) +17° (c 0.8, DMSO), λ_(max).(EtOH) 266.5 nm (ε 33,000), ν_(max). (Nujol) 3270 (NH), 1780 (β-lactam)1520 and 1338 (NO₂), 1675 and 1520 cm.⁻¹ (CONH), τ (DMSO-d₆) valuesinclude 1.58 and 1.69 (two doublets J 8 Hz; p-substituted phenyl), 2.1to 2.5 (multiplet; aromatic protons), 7.79 (singlet; OCOCH₃).

EXAMPLE 313-Acetoxymethyl-7β-(2-ethylcarbamoyloxyimino-2-phenylacetamido)ceph-3-em-4-carboxylicacid (syn-isomer).

To ethyl isocyanate (5 ml.) was added3-acetoxymethyl-7β-(2-hydroxyimino-2-phenylacetamido)ceph-3-em-4-carboxylicacid ethyl acetate solvate (syn-isomer) (0.9 g.) and the mixture stirredfor one hour at room temperature. Two further portions of the isocyanate(5 ml.) were added, over a period of two hours. The mixture was thenallowed to stand for one hour, and poured into petroleum (b.p. 40°-60°;250 ml.) and the resulting precipitate collected, washed thoroughly withpetroleum and dried. The solid was dissolved in ethyl acetate andextracted into sodium bicarbonate solution; the bicarbonate solution wasthen washed with ethyl acetate, acidified (2 N-hydrochloric acid) andextracted with ethyl acetate. The combined extracts were dried andconcentrated, and the concentrate (ca. 5 ml.) added dropwise topetroleum spirit with vigorous stirring. The precipitate formed wasfiltered and dried, giving the title acid (0.4 g.; 47%), [α]_(D) +50° (c0.85, DMSO), λ_(max). (pH 6 buffer) 257.5 nm (ε 21,200), ν_(max).(Nujol) 1782 (β-lactam), 1675 and 1520 cm.⁻¹ (CONH), τ (DMSO-d₆) valuesinclude 0.04 (doublet J 8 Hz; NH), 2.0-2.6 (multiplet; aromaticprotons), 6.7-7.1 (multiplet; NHCH₂ CH₃) and 8.89 (triplet, J 9 Hz; CH₂CH₃).

EXAMPLE 323-Acetoxymethyl-7β-[2-(2-chloroethyl)carbamoyloxyimino-2-phenylacetamido]-ceph-3-em-4-carboxylicacid (syn-isomer)

To a solution of3-acetoxymethyl-7β-(2-hydroxyimino-2-phenylacetamido)ceph-3-em-4-carboxylicacid ethyl acetate solvate (syn-isomer) (1.0 g.) in dimethylformamide(21 ml.) containing triethylamine (0.425 g) was added2-chloroethylisocyanate (0.274 g.) and the mixture was stirred at roomtemperature for one hour. The reaction mixture was acidified (2 Nhydrochloric acid) and extracted with ethyl acetate. The extracts werecombined and extracted with saturated aqueous sodium bicarbonate. Thecombined aqueous extracts were acidified (2 N-hydrochloric acid) andextracted with ethyl acetate, dried, concentrated and added dropwise topetroleum with vigorous stirring. The precipitated solid was filtered,dissolved in ethyl acetate (10 ml.) and added dropwise to petroleum (300ml.). The precipitate was filtered and dried giving the title acid (0.76g; 74%), [α]_(D) +28° (c 1.0 DMSO), λ_(max). (pH 6 phosphate buffer)257.5 nm. (ε 20,780), ν_(max). (Nujol) 3270 (NH), 1780 (β-lactam), 1660and 1520 cm.⁻¹ (amide), τ (DMSO-d₆) values include -0.10 (doublet, J 8Hz; NH), 6.2-6.7 (multiplet; C-2 CH₂ +--CH₂ CH₂ Cl), 7.95 (singlet;OCOCH₃).

EXAMPLE 336β-(2-Hydroxyimino-2-phenylacetamido)-2,2-dimethylpenam-3α-carboxylicacid (syn-isomer)

To a suspension of 6β-amino-2,2-dimethylpenam-3α-carboxylic acid (1.08g) in chloroform (25 ml.) was added hexamethyldisilazane (2.49 g) andthe mixture was heated under reflux for two hours, during which timesolution occurred. The solvents were removed under reduced pressure,giving trimethylsilyl2,2-dimethyl-6β-trimethylsilylaminopenam-3α-carboxylate as a solid. Thesolid was dissolved in methylene chloride (20 ml.) and propylene oxide(1.5 ml.) added. The solution was cooled to 0° and treated dropwise with2-dichloroacetoxyimino-2-phenylacetyl chloride (from 1.38 g.2-dichloroacetoxyimino-2-phenylacetic acid (syn-isomer)) in methylenechloride (20 ml.), over a period of fifteen minutes with stirring. Thesolution was allowed to stir for two hours at room temperature. Thesolvents were evaporation under reduced pressure below 35°, and theresidue taken up in ethyl acetate. After addition of methanol (2 ml.),the solution was extracted as rapidly as possible with ice-cold sodiumbicarbonate solution and the combined extracts washed with ethyl acetateand poured into a stirred mixture of ethyl acetate and 2 N-hydrochloricacid. The organic phase was separated and combined with an ethyl acetateextraction of the aqueous phase, and the solution washed with water,dried and evaporated. The residue was taken up in ethyl acetate (5 ml.)and added dropwise to petroleum (b.p. 40°-60°; 200 ml.). Theprecipitated solid was filtered and dried, giving6β-(2-hydroxyimino-2-phenylacetamido)-2,2-dimethylpenam-3α-carboxylicacid (syn-isomer) (0.84 g; 46%), [α]_(D) +210° (c 0.9, DMSO), λ_(max).(EtOH) 251 nm (ε 9,450), ν_(max). (Nujol) 3650- 2300 (OH), 3280 (NH),1758 (β-lactam), 1735 (CO₂ H), 1650 and 1510 cm.⁻¹ (CONH), τ (DMSO-d₆)0.51 (doublet, J 7 Hz; NH), 2.2-2.7 (multiplet; aromatic protons), 4.28(quartet, J 4 Hz and 7 Hz; C-6H), 4.40 (doublet J 4 Hz; C-5H), 5.27(singlet; C-3H), 8.39 and 8.48 (two singlets; methyl groups).

EXAMPLE 34 Benzyl 2-phenylethylammonium3-acetoxymethyl-7β-(2-hydroxyimino-2-phenylacetamido)ceph-3-em-4-carboxylate(syn-isomer)

To a solution of sodium bicarbonate (0.084 g.) in water (20 ml.) wasadded3-acetoxymethyl-7β-(2-hydroxyimino-2-phenylacetamido)ceph-3-em-4-carboxylicacid ethyl acetate solvate (0.507 g.) and the resulting solution wastreated with a solution of benzyl 2-phenylethyl ammonium acetate (0.396g.) in water (10 ml.). A white solid separated, and after stirring forfifteen minutes it was filtered, washed with water and dried to give thetitle salt (0.2 g; 32%), λ_(max). (pH 6 phosphate buffer) 254 nm (ε18,000), ν_(max). (Nujol) 1773 (β-lactam) 1650 and 1550 cm.⁻¹ (CONH), τ(DMSO-d₆) values include 0.4 (doublet, J 8 Hz; NH), 2.3-2.71 (multiplet;aromatic protons), 7.99 (singlet; OCOCH₃).

EXAMPLE 352,2-Dimethyl-6β-[2-hydroxyimino-2(thien-2-yl)acetamido]-penam-3α-carboxylicacid (syn-isomer)

A solution of trimethylsilyl2,2-dimethyl-6β-trimethylsilylaminopenam-3α-carboxylate [prepared fromthe corresponding amino-acid (0.864 g.)] and propylene oxide (1 ml.) indichloromethane (20 ml.) was cooled to 0° and treated dropwise with asolution of 2-dichloroacetoxyimino(thien-2-yl)acetyl chloridesyn-isomer; [prepared from the corresponding acid (0.753 g.)] indichloromethane (12 ml.) The resuling solution was maintained at 0° for1 hour and was then evaporated to a small bulk and partitioned betweenethyl acetate and saturated sodium bicarbonate solution. The aqueousphase was washed with ethyl acetate, acidified with 2 N-hydrochloricacid, and extracted with ethyl acetate. The dried organic solution wasevaporated to a small bulk and added dropwise to stirred petroleumspirit (b.p. 40°-60°). The resulting precipitate was collected, washed,and dried to afford the title acid (0.337 g., 24% based on amine),[α]_(D) +224° (c 0.57, DMSO), λ_(max). (pH 6 buffer) 288 nm (ε 6,400), λinf. 270 nm (ε 5,800), ν_(max). (Nujol), 2600 and 1730 (CO₂ H), 1776(β-lactam), 1670 and 1526 cm.⁻¹ (CONH), τ (d₆ -DMSO) values include 0.44(d, J 6 Hz; NH), 2.45 and 2.9 (multiplets, aromatic protons), 5.78 (s;C-3H), 8.46 and 8.55 (2 s; CH₃ groups).

EXAMPLE 362,2-Dimethyl-6β-[2-hydroxyimino-2-(thien-3-yl)acetamido]penam-3α-carboxylicacid (syn-isomer)

To a cold solution of trimethylsilyl2,2-dimethyl-6β-trimethylsilylamino-penam-3α-carboxylate [made from6β-amino-2,2-dimethyl-penam-3α-carboxylic acid (0.43 g) andhexamethyldisilazane (2.1 mls.)] and propylene oxide (0.53 mls.) in drymethylene chloride (10 mls.) was added dropwise with stirring a solutionof 2-dichloroacetoxyimino-2-thien-3-yl) acetyl chloride (syn-isomer)(2.1 mmoles) in dry methylene chloride. After 1 hr. at 20° C. thereaction was evaporated and the residue dissolved in ethyl acetate. Theethyl acetate solution was extracted with ice-cold saturated sodiumbicarbonate solution. The combined aqueous phases were acidified to pH 1with 2 N-hydrochloric acid and extracted with ethyl acetate. Afterdrying the extracts were evaporated to a small volume which on adding toan excess of petrol (b.p. 40°-60°) gave a white solid which was filteredand dried to yield the title compound (0.32 g, 44%), [α]_(D) =+220° (c0.9, dioxan), λ_(max). (pH 6 buffer) 256 nm (ε 9,100), ν_(max). (Nujol)3300 (NH), 1770 (β-lactam), 1740 and 2600 (COOH) and 1660 and 1526 cm.⁻¹(CONH) τ (DMSO d₆) includes 0.46 (d; J 8 Hz; NH) 2.30, 2.35, 2.59 (m;thienyl protons), 5.66 (s; C-3H), and 8.35 and 8.44 (2s; CH₃ groups).

EXAMPLE 372,2-Dimethyl-6β-[2-hydroxyimino-2(fur-2-yl)acetamido]-penam-3α-carboxylicacid (syn-isomer)

A solution of trimethylsilyl2,2-dimethyl-6β-trimethylsilyaminopenam-3α-carboxylate [prepared fromthe corresponding amino-acid (0.648 g.)] and propylene oxide (0.75 ml.)in dichloromethane (15 ml.) was cooled to 0° and treated dropwise with asolution of 2-dichloroacetoxyimino(fur-2-yl)acetyl chloride [syn-isomer;prepared from the corresponding acid (0.579 g.)] in dichloromethane (12ml.). The resulting solution was maintained at 0° for 1 hour and wasthen evaporated to small volume and partitioned between ethylacetate andsaturated sodium bicarbonate solution. The aqueous phase was washed withethyl acetate, acidified with 2 N-hydrochloric acid and extracted withethyl acetate. The dried organic solution was evaporated to a small bulkand added dropwise to stirred petroleum spirit (b.p. 40°-60°). Theresulting precipitate was collected, washed and dried to give the titleacid (0.56 g., 55% based on amine), [α]_(D) +243° (c 0.93, DMSO),λ_(max). (pH 6 buffer) 275 nm (ε 9,600), ν_(max). (Nujol), 1778(β-lactam), 1740 and 2600 (CO₂ H), 1670 and 1528 cm.⁻¹ (CONH), τ (d₆-DMSO) values include 0.44 (d, J 6 Hz; NH) 2.18 and 3.34 (multiplets;aromatic protons), 5.70 (s; C-3H), 8.36 and 8.46 (2s; CH₃ groups).

EXAMPLE 383-Acetoxymethyl-7β-[2-hydroxyimino-2-(thien-3-yl)acetamido]ceph-3-em-4-carboxylicacid (syn-isomer)

To an ice cold solution of t-butyl3-acetoxymethyl-7β-aminoceph-3-em-4-carboxylate (1.59 g) and propyleneoxide (3.5 mls) in ethyl acetate (15 mls) was added with stirring a 1-Msolution of 2-dichloroacetoxyamino-2-(thien-3-yl) acetyl chloride(syn-isomer) (5.3 ml.) in ethyl acetate. After 11/2 hrs. at 20° C. thesolution was washed with 2N-HCl, saturated sodium bicarbonate solutionand brine. The organic layer was dried and evaporated to give t-butyl3-acetoxymethyl-7β-[2-dichloroacetoxyimino-2-(thien-3-yl)acetamido]ceph-3-em-4-carboxylate(syn-isomer) as a white foam, (2.8 g, 100%), [α]_(D) +47.0° (c 0.9,DMSO), λ_(max). (ethanol) 253 nm (ε 13,900), ν_(max). (CHBr₃) 3580 (OH),3410 (NH), 1790 (β-lactam), 1728 (OCOCH₃), 1720 (COO Bu^(t)) and 1700and 1520 cm.⁻¹ (CONH); τ (CDCl₃) values include 2.11 to 2.7 (m; thienylprotons), 7.92 (s; OCOCH₃), 8.48 (s; Bu^(t)).

A solution of the t-butyl ester (2.7 g.) in trifluoroacetic acid (25mls.) was allowed to stand for 15 mins. when it was evaporated and theresidue azeotroped with benzene. The oil was dissolved in ethyl acetateand extracted with saturated sodium bicarbonate solution. The aqueoussolution was acidified to pH 1 with 2 N-HCl and extracted with ethylacetate. The combined organic phases were dried and evaporated to asmall volume which on adding to an excess of petrol (b.p. 40°-60°) gavea white solid which was filtered and dried yielding3-acetoxymethyl-7β-[2-hydroxyimino-2-(thien-3-yl)acetamido]ceph-3-cm-4-carboxylicacid (syn-isomer) (1.5 g, 60.3%) [α]_(D) =+50.5° (c 0.88, DMSO),λ_(max). (phosphate buffer pH 6) 256.5 nm (ε 18,350), ν_(max) (Nujol)3280 (NH and OH), 1770 (β-lactam), 1726 (OCOCH₃), 1662 and 1522 (CONH)cm⁻¹ τ (DMSO d₆) values include 0.36 (d; J 8 Hz; --NH--), 2.3 to 2.7 (m;thienyl protons), 4.12 (dd; J 8, 5 Hz; 7H), 4.77 (d, J 5 Hz; 6H), 7.96(s, OCOCH₃).

EXAMPLE 393-Acetoxymethyl-7β-[2-hydroxyimino-2-(fur-2-yl)acetamido]-ceph-3-em-4-carboxylicacid (syn-isomer)

To an ice cold solution of t-butyl3-acetoxymethyl-7β-aminoceph-3-em-4-carboxylate (1.76 g.) and propyleneoxide (4 mls) in ethyl acetate (15 mls) was added with stirring a 1-Msolution of syn-2-dichloroacetoxyimino-2-(fur-2-yl)acetyl chloride inethyl acetate (5.37 ml). After 1 hr at 20° C. the solution was washedsuccessively with 2 N-HCl, saturated sodium bicarbonate solution andbrine. The organic layer was dried and evaporated to give the t-butylester (syn-isomer) as a yellow foam, (3.04 g., 100%), [α]_(D) =+65.5° (c0.9 DMSO), λ_(max) (ethanol) 270 nm (c ε 16,700), ν_(max). (CHBr₃), 3300(NH), 1780 (β-laciam), 1726 (OCOCH₃ and COO^(t) Bu), and 1680 and 1530cm.⁻¹ (CONH), τ (CDCl₃) values include 2.31, 2.88 and 3.39 (multiplets,furyl protons), 3.76 (s; CHCl₂), 7.92 (s; OCOCH₃), 8.48 (s; Bu^(t)).

A solution of the above t-butylacetoxymethyl-7β-[2-dichloroacetoxyimino-2-(fur-2-yl)-acetamido]-ceph-3-em-4-carboxylate(syn-isomer) (2.94 g.) in trifluoroacetic acid (20 mls) was allowed tostand for 15 mins. when the solvent was evaporated and the residueazeotroped with benzene. The oil was dissolved in ethyl acetate andextracted with saturated sodium bicarbonate solution. The aqueoussolution was acidified to pH 1 with 2 N-hydrochloric acid and extractedwith ethyl acetate. The combined organic phases were dried andevaporated to a small volume which on adding to an excess of petrol(b.p. 40°-60°) gave a white solid which was filtered and dried to yield3-acetoxymethyl-7β-[2-hydroxyimino-2-(fur-2-yl)acetamido]ceph-3-em-4-carboxylicacid, (1.68 g, 76%) [α]_(D) +69° (c 1.2, DMSO), λ_(max) (pH 6 buffer)269 nm (ε 16,300), ν_(max). (Nujol) 1782 (β-lactam), 1728 (OCOCH₃), 1720and 2600 (--COOH), and 1680 and 1536 cm⁻¹ (CONH), τ (DMSO-d₆) valuesinclude 0.33 (d, J 8 Hz; NH), 2.19 and 3.36 (2s; furyl protons), 6.28and 6.52 (2 doublets, branches of quartet, J 18 Hz; C-2CH₂) and 7.95 (s;OCOCH₃).

EXAMPLE 40 3-Acetylthiomethyl-7β-[2-hydroxyimino-2-(thien-2-yl)acetamido]ceph-3-em-4-carboxylic acid(syn-isomer)

Diphenylmethyl 3-acetylthiomethyl-7β-aminoceph-3-em-4-carboxylatehydrochloric (1.03 g) was partitioned between ethyl acetate (30 ml) andaqueous sodium bicarbonate solution (30 ml.). The ethyl acetate layerwas separated, washed with saturated sodium chloride solution, dried andfiltered. The resulting solution was treated with 1-M solution of2-dichloroacetoxyimino-2-(thien-2-yl)-acetyl chloride (syn-isomer) inethyl acetate (2.15 ml.) and propylene oxide (0.5 ml.) and stirred at21° for 40 mins, during which time a white precipitate appeared andre-dissolved. The solution was washed successively with aqueous sodiumbicarbonate solution, water, saturated sodium chloride solution anddried. Removal of the solvent in vacuo gave an off-white froth (1.42 g).This was dissolved in anisole (2 ml.) and trifluoroacetic acid (% ml.)added. After 5 min. at 10°, the reagents were removed in vacuo and theresulting gum partitioned between ethyl acetate and aqueous sodiumbicarbonate solution. The organic layer was re-extracted with sodiumbicarbonate solution and the combined aqueous layers were washed withethyl acetate. The aqueous layer was adjusted to pH 2.0 withhydrochloric acid (2 N) and extracted with ethyl acetate. The extractswere washed with saturated sodium chloride solution, dried, and thesolvent removed in vacuo to give the title compound as a pale brownfroth (0.97 g) [ α]_(D) -52° (c 1.04, DMSO), λ_(max), (pH 6 buffer) 266nm (ε13,400) ν_(max). (Nujol) 2600,1720 (CO₂ H), 1770 (β-lactam), 1740(SCOCH₃), 1660 and 1520 cm.⁻¹ (CONH), τ (DMSO-d₆) values include 0.30(d, J 9; NH), 2.40, 2.84 (m, thien-2-yl), 7.66 (s; SCOCH₃).

The ester used as starting material for the above acylation was preparedas follows:

(a) Diphenylmethyl3-acetylthiomethyl-7β-formamidoceph-3-em-4-carboxylate, 1β-oxide

A solution of diphenylmethyl3-bromomethyl-7β-formamidoceph-3-em-4-carboxylate, 1β-oxide (5.0 g) inN,N-dimethylformamide (30 ml.) was treated with ethanethiolic acid (4.0ml) and triethylamine (1.4 ml.) and the reaction stirred for 1.6 hr. at+19°. The yellow solution was poured into water (100 ml.) and ethylacetate (100 ml.) and the resulting insoluble solid was collected,washed with ethyl acetate and dried in vacuo over phosphorus pentoxide,to give diphenylmethyl3-acetylthiomethyl-7β-formamidoceph-3-em-4-carboxylate, 1β-oxide (2.422g, 49%), mp 198°-199° (dec.), [α]_(D) -60° (c 1.0, DMSO), λ_(max).(EtOH) 273 nm (ε 10,300), ν_(max). (CHBr₃) 3430 (NH), 1803 (β-lactam)1725 (CO₂ R), 1695, 1505 (CONH), 1042 cm.⁻¹ (S→O) τ (DMSO-d₆), 1.66 (d,J 9; NH), 1.78 (s; CHO), 2.59 (m, phenyl), 3.01 (s, CHPh₂), 7.68 (s;SCH₃).

(b) Diphenylmethyl3-acetylthiomethyl-7β-formamidoceph-3-em-4-carboxylate

A stirred solution of diphenylmethyl3-acetylthiomethyl-7β-formamidoceph-3-em-4-carboxylate, 1β-oxide (1.00g) in dry N,N-dimethylformamide (15 ml.) was cooled to -5° and treatedwith potassium iodide (0.67 g) and acetyl chloride (0.315 g). The brownsolution was stirred for 5 min. at 0°, then for 30 min. after removal ofthe ice-bath. A solution of sodium metabisulphite (0.60 g) in water (12ml) was added, and the yellow suspension was stirred for 5 mins. at 20°,then poured into water (200 ml.) and extracted with dichloromethane. Thecombined extracts were washed with water, dried and the solvent removedin vacuo to give diphenylmethyl3-acetylthiomethyl-7β-formamidoceph-3-em-4-carboxylate as a pale yellowpowder (0.92 g, 94%), [α]_(D) -136° (c 1.0, DMSO), λ_(max). 268 nm(EtOH) (ε 8,950).

(c) Diphenylmethyl 3-acetylthiomethyl-7β-aminoceph-3-em-4-carboxylatehydrochloride

A stirred suspension of diphenylmethyl3-acetylthiomethyl-7β-formamidoceph-3-em-4-carboxylate (0.505 g) inmethanol:ether (1:1, 3 ml.) at 0° was treated over 10 min. withphosphorus oxychloride (0.468 g.) The ice bath was removed and stirringcontinued for a further 20 min, when a clear solution resulted. Thereaction was cooled to 0°, and a white crystalline precipitate appeared.Ether (15 ml.) was added and the precipitate filtered off, washed withether and dried in vacuo to give diphenylmethyl3-acetylthiomethyl-7β-aminoceph-3-em-4-carboxylate hydrochloride (0.456g, 89%) as white microcrystals; m.p. 155°-160° (d) [α]_(D) -91° (c 0.83in DMSO), λ_(max) (EtOH) 268 nm (ε 8,700), ν_(max). (Nujol) 1770(β-lactam), 1720 (CO₂ R), 1702 cm.⁻¹ (SCOCH₃), τ (DMSO-d₆) valuesinclude 2.60 (m; Ph), 3.02 (s, CHPh₂), 7.66 (s, SCOCH₃).

EXAMPLE 413-Crotonoyloxymethyl-7β-[2-hydroxyimino-2-(thien-2-yl)acetamido]ceph-3-em-4-carboxylicacid (syn-isomer)

A molar solution of 2-dichloroacetoxyimino-2-(thien-2-yl) acetylchloride (syn-isomer) in ethyl acetate (2.15 ml.) was added to asolution of diphenylmethyl7β-amino-3-crotonoyloxymethylceph-3-em-4-carboxylate (0.933 g) in ethylacetate (15 ml.) containing propylene oxide (0.6 ml). After 30 minutesthe solution was washed with 2 N-hydrochloric acid, sodium bicarbonatesolution, water and brine, dried and concentrated to a foam (1.575 g.).

A solution of this foam (1.464 g) in anisole (2 ml) was treated withtrifluoroacetic acid at 20°. After 5 minutes the solution wasconcentrated. The oily residue was dissolved in ethyl acetate and thesolution was washed with water. The ethyl acetate solution was thenthrice extracted with dilute sodium bicarbonate solution. The combinedextracts were washed with ethyl acetate and then taken to pH 2 withconcentrated hydrochloric acid. The solution was extracted with ethylacetate and the extract was washed with water and brine, dried andconcentrated to a foam. Addition of ethyl acetate to this foam producedcrystals which were filtered off and washed with ethyl acetate to givethe title oxime, [α]_(D) ²⁵ +60° (c 1 in DMSO) λ_(max). (pH 6 phosphatebuffer) 261 nm (ε 16,270) ν_(max). (Nujol) include 1775 (β-lactam), 1733(unsaturated ester), 1658 and 1545 (CONH) and 960 cm⁻¹ (trans CH═CH) τ(DMSO-d₆) values include 0.26 (doublet 8 Hz, NH) 2.38 and 2.83 (2multiplets; thienyl protons) 6.29 and 6.49 (doublets, J 18 Hz; C-2H₂),8.13 (doublets J 7 and 1 Hz; --CH═CH--CH₃).

EXAMPLE 427β-[2-Hydroxyimino-2-(thien-2-yl)-acetamido]-3-(1-phenyltetrazol-5-ylthiomethyl)-ceph-3-em-4-carboxylic acid (syn-isomer)

A solution of 2-dichloroacetoxyimino-2-(thien-2-yl)-acetyl chloride(syn-isomer) in methylene dichloride (7 mls of 15% solution, ca. 3.5mmole) was added, over 5 minutes, to a stirred solution ofdiphenylmethyl7β-amino-3-(1-phenyltetrazol-5-ylthiomethyl)-ceph-3-em-4-carboxylatehydrochloride (1.779 g.) and propylene oxide (1.5 ml.) in dry methylenedichloride (25 ml.). After stirring for a further 20 minutes at 23°, thesolution was washed successively with saturated sodium bicarbonate,water, and brine (25 ml. of each), and dried and evaporated to a foam(2.62 g.). A solution of this foam in benzene (10 ml.) was purified bychromatography on kieselgel with benzene:ethyl acetate (10:1), aseluent. Appropriate fractions were combined and evaporated to dryness invacuo to give diphenylmethyl7β-[2-hydroxyimino-2-(thien-2-yl)-acetamido]-3-(1-phenyltetrazol-5-yl-thiomethyl)-ceph-3-em-4-carboxylateas a foam (1.27 g). A solution of this foam in trifluoroacetic acid (5ml.) and anisole (1 ml.) was kept at 23° for 5 minutes, and the solventswere removed in vacuo at 40°. The residue was dissolved in ethyl acetate(50 ml.), the solution extracted with sodium bicarbonate solution, andthe alkaline extract covered with ethyl acetate (100 ml.) and acidified(to pH 2) with 2 N-hydrochloric acid. The organic phase was separated,and washed with water, and brine, dried and evaporated to a foam (750mg.). A solution of this foam in ethyl acetate was added to petroleum togive the title acid as a pale-yellow solid (469 mg., 29%), [α]_(D)-51.4° (c 0.91, acetone), λ_(max). (pH 6 phosphate buffer) 264 nm (ε19,500), ν_(max). (Nujol) 3320 (NH), 1784 (β-lactam), 1722 (CO₂ H), and1674 and 1530 cm.⁻¹ (CONH), τ (DMSO-d₆) 0.26 (NH, doublet, J 8 Hz.),2.31 (s;Ph), 4.13 (C 7-H, double doublet, J 5 and 8 Hz.), 4.82 (C 6-H,doublet, J 5 Hz.), 5.39 and 5.73 quartet, J 13 Hz; C-3 CH₂), and 6.28(s; C-2 CH₂).

The amino ester used as starting material in the above acylation wasprepared in a similar manner to the amino-ester described in Example 46the 5-mercapto-2-phenyl-1,3,4-oxadiazole being replaced by5-mercapto-1-phenyltetrazole, to give diphenylmethyl7β-amino-3-(1-phenyltetrazol-5-ylthiomethyl)-ceph-3-em-4-carboxylatehydrochloride λ_(max) (EtOH) 251.5 nm. (ε 10,000), ν_(max). (CHBr₃) 1782(β-lactam), and 1720 cm.⁻¹ (CO₂ R), τ (DMSO-d₆) values include 2.32(Ph--N<), 4.73 (C-6 H and C-7 l.), 5.32 and 5.68 (C-3 CH₂, quartet, J 14Hz.), and 6.10 (C-2 CH₂).

EXAMPLE 437β-[2-Hydroxyimino-2-(thien-2-yl)-acetamido]-3-(1-methyltetrazol-5-ylthiomethyl)-ceph-3-em-4-carboxylicacid (syn-isomer)

A solution of 2-dichloroacetoxyimino-2-(thien-2-yl)acetyl chloride(syn-isomer) in dry methylene dichloride (6 ml. of 15% solution, ca. 3mmole.) was added, over 5 minutes, to a solution of diphenylmethyl7β-amino-3-(1-methyltetrazol-5-ylthiomethyl)-ceph-3-em-4-carboxylate(1.24 g.) and propylene oxide (0.8 ml.) in methylene dichloride (20ml.). After stirring for 30 minutes at 23°, aqueous sodium bicarbonatewas added, and the two-phase mixture stirred for a further 30 minutes.The organic phase was separated, and washed with brine, and dried andevaporated to a foam (2.0 g.). A solution of this foam in benzene (20ml.) was purified by chromatography on kieselgel with benzene; ethylacetate (5:1) as eluent. Appropriate fractions were combined andevaporated in vacuo to give diphenylmethyl7β-[2-hydroxyimino-2-(thien-2-yl)-acetamido]-3-(1-methyltetrazol-5-ylthiomethyl)-ceph-3-em-4-carboxylateas a foam (1.68 g.). A solution of this foam in trifluoroacetic acid (6ml) and anisole (1.5 ml) was kept at 23° for 5 minutes, and the solventswere removed at 40° (2 mm). The residue was dissolved in ethyl acetate(30 ml.), and the solution extracted with sodium bicarbonate solution.The alkaline extract was covered with ethyl acetate, and acidified to pH2 with 2 N-hydrochloric acid. The organic phase was separated, andwashed with water, and brine, and the solvent evaporated in vacuo. Theresidue was dissolved in acetone, the solution treated with somecharcoal and filtered through a pad of kieselguhr; the filtrate wasdried and evaporated to a foam (1.085 g.). A solution of this foam inethyl acetate was run into petroleum to give the title acid as acolourless, amorphous solid (852 mg, 71%) [α]_(D) ²³ -90° (c 0.91,acetone), λ_(max). (pH 6 phosphate buffer) 267.5 nm, (ε 18,000), ν_(max)(Nujol) 3290 (NH), 1780 (β-lactam), 1720 (CO₂ H), and 1670 and 1530cm.⁻¹ (CONH), τ (DMSO-d₆) values include 0.25 (NH, doublet, J 8 Hz.),4.14 (C-7 H, double doublet, J 4.5 and 8 Hz.), 4.79 (C-6 H, doublet, J4.5 Hz), 6.05 (CH₃).

In a similar manner was prepared:

EXAMPLE 447β-[2-Hydroxyimino-2-(fur-2-yl)acetamido]-3-(1-methyltetrazol-5-ylthiomethyl)-ceph-3-em-4-carboxylicacid (syn-isomer)

[α]_(D) ²² -102° (c 0.9 acetone), λ_(max). (pH 6 phosphate buffer) 273.5nm (ε 20,700) ν_(max). (Nujol) 3280 (NH), 1780 (β-lactam), 1720 (CO₂ H)and 1674 and 1530 cm.⁻¹ (CONH), τ (DMSO-d₆) values include 0.33 (NH,doublet J 8 Hz), and 6.07 (CH₃).

The starting ester for the acylations in Examples 43 and 44 was preparedby the following route:

(a) Diphenylmethyl3-(1-methyltetrazol-5-ylthiomethyl)-7β-(2-thienylacetamido)-ceph-3-em-4-carboxylate

A solution of diphenylmethyl3-bromomethyl-7β-(2-thienylacetamido)-ceph-3-em-4-carboxylate (17.505g.) and 5-mercapto-1-methyltetrazole (3.486 g.) in dry tetrahydrofuran(250 ml.) was stirred at 10° and treated, over 5 minutes, with asolution of triethylamine (4.16 ml.) in dry tetrahydrofuran (50 ml.).The resulting suspension was stirred for a further 45 minutes (duringwhich time the temperature was allowed to rise to ca. 20°) and thenadded, over 5 minutes, to a stirred mixture of 2 N-hydrochloric acid (50ml.), water (700 ml.), brine (700 ml.), and ethyl acetate (1.5 l.). Theorganic phase was separated, washed with 2 N-hydrochloric acid, waterand brine, treated with some charcoal and filtered through a pad ofkieselguhr. The filtrate was dried and evaporated to a foam (20.6 g.).This foam was dissolved in hot methanol (200 ml.), and the solutioncooled to give the ester as colourless plates (14.391 g., 77.5%),λ_(max). (EtOH) 264 nm, (ε8,700), ν_(max). (CHBr₃) 3420 (NH), 1780(β-lactam), 1710 (CO₂ R), and 1680 and 1502 cm.⁻¹ (CONH), τ (CDCl₃)values include 3.40 (NH, doublet, J 9 Hz.), (C.7 H, double doublet, J 5and 9 Hz.), 5.02 (C-6 H, doublet, J 5 Hz.), 6.19 (CH₃).

(b) Diphenylmethyl7β-amino-3-(1-methyltetrazol-5-yl-thiomethyl)-ceph-3-em- 4-carboxylate

A suspension of phosphorus pentachloride (416 mg) in dry methylenedichloride (10 ml.) was stirred at 23° and a solution of pyridine (0.16ml) added. The warm suspension was stirred for 10 minutes, and cooled to0°, and treated, over 10 minutes, with a solution of diphenylmethyl3-(1-methyltetrazol-5-ylthiomethyl)-7β-(2-thienylacetamido)-ceph-3-em-4-carboxylate(619 mg) in methylene dichloride (15 ml.). After stirring for a further45 minutes, during which time the temperature was allowed to rise to23°, the solution was added, over 5 minutes, to a stirred and cooled(0°) mixture of methanol (5 ml.) and methylene dichloride (15 ml.). Theresulting solution was stirred for a further 10 minutes, and washed withN-hydrochloric acid (20 ml.), and stirred for 30 minutes with saturatedsodium bicarbonate sodium (50 ml.). The organic phase was separated, andwashed with saturated aqueous sodium bicarbonate (25 ml.), and treatedwith some charcoal. The mixture was filtered through a pad ofkieselguhr, and the filtrate evaporated to a gum (640 mg.), which wastriturated with ether (20 ml) to give the amine as an off-white solid(403 mg, 81.5%), λ_(max). (CHCl₃) 268.5 nm (ε 7,700), ν_(max). (CHBr₃)3416 and 3350 (NH₂), 1780 (β-lactam), and 1720 cm.⁻¹ (CO₂ R), τ (CDCl₃)values include 5.00 and 5.15 (C-6H and C-7 H, two doublets, J 5 Hz.),6.14 (CH₃ --), and 7.59 (NH₂).

EXAMPLE 45

In a similar manner to Example 43, acylation of diphenylmethyl7β-amino-3-(5-methyl-1,3,4-thiadiazolyl-2-)-thiomethylceph-3-em-4-carboxylatewith syn-2-dichloroacetoxyimino-2-(fur-2-yl)acetyl chloride andsubsequent deprotection gave 7β-[2-hydroxyimino-2-(fur-2-yl)acetamido]-3-(5-methyl-1,3,4-thiadiazol-2-yl)thiomethylceph-3-em-4-carboxylicacid (syn-isomer), τ (DMSO-d₆) values inside 0.36 (d, J 9 Hz, NH); 2.23;3.39 (25, furyl protons); 4.19 (dd, J 5 and 9 Hz, C.7 H), 4.83 (d, J5Hz, C-6 H), 5.45, 5.90 (q, J 14 Hz, C-3 CH₂), 6.21, 6.44 (q, J 18 Hz,C-2 H₂) 7.33 (S, CH₃).

EXAMPLE 467β-[2-Hydroxyimino-2-(thien-2-yl)-acetamido]-3-(5-phenyl-1,3,4-oxadiazol-2-ylthiomethyl)-ceph-3-em-4-carboxylicacid (syn-isomer)

A solution of 2-dichloroacetoxyimino-2-(thien-2-yl)-acetyl chloride(syn-isomer) in methylene dichloride (7 ml. of 15% solution; was added,over 5 minutes, to a stirred solution of diphenylmethyl7β-amino-3-(5-phenyl-1,3,4-oxadiazol-2-ylthiomethyl)-ceph-3-em-4-carboxylatehydrochloride (1.779 g.) and propylene oxide (1.5 ml.) in dry methylenedichloride (25 ml.). After stirring for a further 30 minutes, thesolution was washed with saturated aqueous sodium bicarbonate, water andbrine (25 ml. of each), and dried and evaporated to a foam (2.34 g.). Asolution of this foam in benzene (10 ml.) was purified by chromatographyon kieselgel with benzene:ethyl acetate (10:1) as eluent. Appropriatefractions were combined and evaporated to dryness in vacuo, and theresidue was triturated with ether (25 ml.) to give diphenylmethyl7β-[2-hydroxyimino-2-(thien-2-yl)-acetamido]-3-(5-phenyl-1,3,4-oxadiazol-2-ylthiomethyl)-ceph-3-em-4-carboxylateas colourless prisms (870 mg., 41%). A suspension of this ester (810 mg)in a mixture of trifluoroacetic acid (3 ml.) and anisole (0.8 ml.) wasshaken at 23° until all the solid had dissolved (ca. 10 minutes.). Thereagents were evaporated at 40° (2 mm), and the residue was dissolved inethyl acetate. The solution was extracted with aqueous sodiumbicarbonate, the alkaline extract covered with ethyl acetate andacidified to pH 2 with 2N-hydrochloric acid. The organic phase wasseparated, and washed with water, and brine and the solvent evaporatedin vacuo. The residue was dissolved in acetone, the solution treatedwith some charcoal and filtered through a pad of kieselguhr; thefiltrate was dried and evaported to a foam (470 mg.). A solution of thisfoam in ethyl acetate was run into petroleum to give the title acid as acolourless, amorphous solid (410 mg., 66%), [α]_(D) ²³ -118° (c 1.08,acetone), λ_(max). (pH 6 phosphate buffer) 274 nm (ε 28,800), ν_(max).(Nujol) 3280 (NH), 1786 (β-lactam), 1720 (CO₂ H), and 1672 and 1530cm.⁻¹ (CONH), τ (DMSO-d₆) values include 0.24 (NH, doublet, J 8 Hz.),4.15 (C-7 H, double doublet, J 4.5 and 8 Hz.), 4.78 (C-6 H, doublet, J4.5 Hz.).

The amino-ester used for the above acylation was prepared in thefollowing manner:

Diphenylmethyl7β-amino-3-(5-phenyl-1,3,4-oxadiazol-2-ylthiomethyl)-ceph-3-em-4-carboxylatehydrochloride p A solution of diphenylmethyl3-bromomethyl-7β-formamidoceph-3-em-4-carboxylate-1β-oxide (10.07 g.)and 5-mercapto-2-phenyl-1,3,4-oxadiazole (3.564 g.) in dryN,N-dimethylformamide (250 ml.) was stirred at 0° and treated, over 10minutes, with a solution of triethylamine (3.2 ml.) inN-dimethylformamide (20 ml.). The resulting solution was stirred for afurther 21/2 hours, during which time the temperature was allowed torise to ca. 20°, and then the solvent was evaporated at 40° in vacuo.The residue was partitioned between methylene dichloride (250 ml.), andwater (150 ml), and the organic phase separated, washed with2N-hydrochloric acid, water, and brine, and dried and the solventevaporated to give diphenylmethyl7β-formamido-3-(5-phenyl-1,3,4-oxadiazol-2-ylthiomethyl)-ceph-3-em-4-carboxylate-1β-oxideas an orange solid (12.076 g.). A suspension of this material in drymethylene dichloride (250 ml.) was stirred at -20° and treated, over 10minutes, with a solution of phosphorus tribromide (5.7 ml.) in methylenedichloride (25 ml.). The resulting solution was stirred for a further 1hour at -10° to -15° and then added, over 10 minutes, to a stirred andcooled (0° ) mixture of methylene dichloride and saturated sodiumbicarbonate solution). The two-phase system was stirred for a further 1hour at ca. 23°; the organic phase was separated, and washed withsaturated sodium bicarbonate solution, and brine, and treated with somecharcoal. The suspension was filtered, and the filtrate dried andevaporated in vacuo to give diphenylmethyl7β-formamido-3-(5-phenyl-1,3,4-oxadiazol-2-ylthiomethyl)-ceph-3-em-4-carboxylateas a foam (11.231 g.). A suspension of this foam in a mixture ofmethanol(100 ml.) and ether (100 ml.) was stirred at 0° and treated,over 20 minutes, with phosphorus oxychloride (3.4 ml). After stirringfor a further 3 hours, the suspension was poured into ether (200 ml.) togive the title hydrochloride as a light-brown solid (8.707 g., 77%),λ_(max). (EtOH) 272 nm. (ε 21,200), ν_(max). (Nujol) 1790 (β-lactam),and 1720 cm.⁻¹ (CO₂ R), τ (DMSO-d₆) values include 4.70 (C-6 H and C-7H), 5.42 and 5.65 (C-3 CH₂ quartet J 13 Hz.). EXAMPLE 473-Acetoxymethyl-7β-[2-ethoxycarbonyloxyimino-2-(thien-2-yl)-acetamido]ceph-3-em-4-carboxylicacid (syn-isomer)

To a solution of sodium3-acetoxymethyl-7β-[hydroxyimino-2-(thien-2-yl)acetamido]ceph-3-em-4-carboxylate(syn-isomer; 0.6 g) in saturated aqueous sodium bicarbonate solution (25ml.) was added a solution of ethyl chloroformate (1.5 ml.) in ethylacetate (20 ml.) and the whole shaken vigorously for one minute. Thebicarbonate phase was separated and shaken with a second portion ofethyl chloroformate (1.0 ml) in ethyl acetate (20 ml.). The bicarbonatephase was separated, washed with ethyl acetate, acidified and extractedwith ethyl acetate. The combined extracts were dried and concentrated toca 5 ml. The concentrate was added dropwise with stirring to petroleum(b.p. 40°-60°; 200 ml.). The precipitated solid was filtered and driedto give the title acid (0.47 g) [α]_(D) +42° (c 0.9 DMSO), λ_(max). (pH6 phosphate buffer) 265 nm. (ε 16,900), ν_(max). (Nujol) 3290 (NH), 1784(β-lactam), 1740 (acetate), 1690 and 1550 cm.⁻¹ (CONH), τ (DMSO-d₆)values include -0.16 (d; J 9 Hz; NH), 2.08, 2.53, 2.74 (three quartets;thienyl protons), 5.70 (q; J 8 Hz; --CH₂ CH₃), 7.96 (s; OAc), 8.72 (t; J8 Hz; --CH₂ CH₃).

EXAMPLE 487β-[2-Acetoxyimino-2-(thien-2-yl)acetamido]-3-acetoxymethylceph-3-em-4-carboxylicacid (syn-isomer)

A solution of sodium3-acetoxymethyl-7β-[2-hydroxyimino-2-(thien-2-yl)actamido]ceph-3-em-4-carboxylate(syn-isomer; 0.7 g) in water (20 ml.) was stirred with ethyl acetate (50ml.) and the pH of the aqueous layer adjusted to 1 with 2N hydrochloricacid. The ethyl acetate phase was separated, combined with an ethylacetate extraction of the aqueous phase, dried and evaporated to give anoil. The oil was dissolved in ethyl acetate (28 ml.) containing pyridine(2.1 g.) and treated dropwise with stirring at room temperature, with asolution of acetyl chloride (1.4 g) in ethyl acetate (14 ml.). Afterstirring for twelve minutes, the mixture was poured into 2N-hydrochloricacid, the ethyl acetate layer separated, washed with water, andextracted with saturated aqueous sodium bicarbonate solution. Thecombined extracts were washed with ethyl acetate, acidified (2Nhydrochloric acid) and extracted three times with ethyl acetate. Thecombined organic extracts were dried, concentrated to 5 ml. and addeddropwise to petroleum (b.p. 40°-60°; 250 ml.). The precipitated solidwas filtered and dried to give the title acid (0.5 g.; 68%), λ_(max).(pH 6 phosphate buffer) 265 nm. (ε 15,500), ν_(max). (Nujol) 3270 (NH),1780 (β-lactam), 1736 (acetate), 1680 and 1540 cm.⁻¹ (CONH), τ (DMSO-d₆)values include -0.15 (d; J 9 Hz; NH), 2.08, 2.54, 2.73 (thien-2-ylprotons), 7.79 (s; ═NOCOCH₃), 7.94 (singlet, OCOCH₃)

EXAMPLE 493-Acetoxymethyl-7β-(2-chloroethylcarbamoyloxyimino)-2-(thien-2-yl)acetamido]ceph-3-em-4-carboxylicacid (syn-isomer)

A solution of sodium3-acetoxymethyl-7β-[2-hydroxyimino-2-(thien-2-yl)acetamido]ceph-3-em-4-carboxylate(syn-isomer; 0.89 g) in dimethylformamide (11 ml.) containingtriethylamine (0.22 g) was treated with 2-chloroethylisocyanate (0.25g). The solution was allowed to stand at room temperature for thirtyminutes, then at 5° for a further hour. It was poured into cold (5°) 2Nhydrochloric acid, extracted three times with ethyl acetate, and thecombined extracts washed with 2N-hydrochloric acid then water thenextracted three times with a cold (5°) saturated aqueous sodiumbicarbonate solution. The combined aqueous extracts were washed withethyl acetate, acidified (2N-hydrochloric acid) and rapidly extractedwith ethyl acetate. The combined extracts were dried, concentrated toca. 5 ml., and the concentrate added dropwise to petroleum (b.p. 40°-60°250 ml.) The precipitated solid was filtered and dried to give the titleacid (0.8 g; 76%), [α]_(D) +33° (c 0.7 DMSO) λ_(max). (pH 6 phosphatebuffer) 264 nm. (ε 17,200), ν_(max). (Nujol), 1786 (β-lactam), 1734(acetate), 1682 and 1508 cm.⁻¹ (CONH), τ (DMSO-d₆) values include -0.12(doublet J 9 Hz; NH), 2.12, 2.56, 2.74 (three quartets; thienylprotons), 7.97 (s; OCOCH₃).

EXAMPLE 50N-[7β-(2-Hydroxyimino-2-(fur-2-yl)acetamido)ceph-3-em-3-ylmethyl]-4'-carbamoylpyridinium4-carboxylate (syn-isomer)

A solution of3-acetoxymethyl-7β-[2-hydroxyimino(fur-2-yl)acetamido]ceph-3-em-4-carboxylicacid (2.5 g.) and isonicotinamide (2.5 g.) in water was heated at65°-70° under nitrogen for 31/2 hours. The cooled mixture was passeddown a column of AG1X8 resin (acetate form) and eluted with water.Fractions were combined on the basis of electrophoretograms andfreeze-dried to a white powder which was washed well with acetone anddried to afford the title compound (0.834 g., 29%), [α]_(D) -61° (c0.84, DMSO), λ_(max). (pH 6 bufer) 267.5 nm (ε 19,500), ν_(max) (Nujol)3340 (NH), 1772 (β-lactam), 1680 and 1560 (CONH), 1608 cm.⁻¹ (CO₂ ⁻), τ(d₆ -DMSO) values include 0.40, 1.26, 1.50 and 1.75 (multiplets,aromatic protons), 1.26 and 1.75 (broad singlets; CONH₂), 4.26(multiplet; C-7H), 4.28 and 4.77 (C-3 CH₂), 4.88 (d, J 5 Hz; C-6 H).

EXAMPLE 513-Acetoxymethyl-7β-[2-hydroxyimine-2-(pyrid-4-yl)acetamido]ceph-3-em-4-carboxylicacid trifluoroacetic acid salt (syn-isomer). (a) t-Butyl3-acetoxymethyl-7β-(pyrid-4-ylacetamido) ceph-3-em-4-carboxylate

A suspension of pyrid-4-ylacetyl chloride hydrochloride (6.0 g.) inethyl acetate (50 ml.) containing propylene oxide (12 ml.) was stirred,cooled in ice and treated dropwise with a solution of t-butyl3-acetoxymethyl-7β-aminoceph-3-em-4-carboxylate (5.0 g.) in ethylacetate (50 ml.). The mixture was stirred at 20° for 20 hours and thenwashed with saturated sodium bicarbonate solution and extracted with 2Nhydrochloric acid. The aqueous extract was washed with ethyl acetate,neutralised with saturated sodium bicarbonate solution and extractedwith ethyl acetate. The extract was washed with water, dried overmagnesium sulphate and evaporated to small bulk whereuponcrystallization began. The crystalline solid was washed well withpetroleum spirit (bp. 40°-60°) and dried to give the title ester as abuff coloured powder (5.4 g., 80% based on amine). A portion (250 mg.)was recrystallised from ethyl acetate as white needles (170 mg.),[α]_(D) +94° (c 0.9, DMSO) ε_(max). (EtOH) 256.5 nm (ε 9,900), ν_(max).(CHBr₃) 3412 (NH)⁻, 1784 (β-lactam), 1736 (OAc), 1722 (CO₂ R), 1690 and1512 cm.⁻¹ (CONH), τ (d₆ -DMSO) 0.81 (d, J 8 Hz; NH), 1.47 and 2.68 (2d,J 5 Hz; aromatic protons), 4.27 (q, J 8 and 5 Hz; C-7H), 4.85 (d, J 5Hz; C-6 H), 5.01 and 5.36 (2d, J 13 Hz; C-3CH₂), 6.38 (s; CH₂ CONH),6.39 (s; C-2CH₂), 7.96 (s; OCOCH₃), and 8.50 (s; C(CH₃)₃).

(b) t-Butyl3-acetoxymethyl-7β-[2-hydroxyimino(pyrid-4-yl)acetamido]-ceph-3-em-4-carboxylate

A solution of t-butyl3-acetoxymethyl-7β-(pyrid-4-ylacetamido)ceph-3-em-4-carboxylate (3.0 g.)in acetic acid (30 ml.) was stirred, cooled briefly in ice and treateddropwise over 3-4 minutes with a solution of sodium nitrite (1.38 g.),in water (10 ml.). The mixture was stirred at 20° for 30 minutes and wasthen diluted with water and extracted with ethyl acetate. The organicextract was washed with saturated sodium bicarbonate solution and waterand then dried over magnesium sulphate. Evaporation almost to drynessgave a residue which was dissolved in the minimum volume of acetone andadded dropwise to stirred petroleum spirit (bp. 40°-60°). The resultingsolid was collected, washed with petroleum spirit and dried to yield thetitle oxime as a white powder (2.9 g., 91%) which was shown (NMR) to bea syn/anti-mixture (30:/0).

The oxime mixture (2.5 g) was chromatographed on silica gel and elutedwith methanol-chloroform (1:49) to give the title compound (anti-isomer,1.09 g., 44% from mixture).

Further elution with methanol-chloroform (1:49) gave material which wasdissolved in acetone and added to stirred petroleum (bp. 40°-60°) toafford t-butyl3-acetoxymethyl-7β-[2-hydroxyimino(pyrid-4-yl)acetamido]ceph-3-em-4-carboxylate(syn-isomer, 0.81 g., 32% from mixture), [α]_(D) +57° (c 1.11, DMSO),λ_(max). (EtOH) 253.5 nm (ε17,600), λ_(max). (Nujol) 3220 (NH), 1784(β-lactam), 1744 (OAc), 1710 (CO₂ R) 1640 and 1526 cm.⁻¹ (CONH), τ (d₆-DMSO) -2.26 (s; NOH), 0.27 (d, J 8 Hz; NH), 1.33 and 2.47 (2d, aromaticprotons), 4.04 (q, J 5 and 8 Hz; C-7H), 4.71 (d, J 5 Hz; C-6H), 4.98 and5.33 (2d, J 13 Hz; C-3 CH₂), 6.20 and 6.53 (2d, J 18 Hz; C-2 CH₂) 7.94(s, OCOCH₃), 8.49 (s, C(CH₃)₃).

(c) The syn-t-butyl ester (0.6 g.) in trifluoroacetic acid (15 ml.) wasstood at 20° for 15 min. and then evaporated to dryness. The residue wastreated with acetone and the solvent removed in vacuo, this process wasthen repeated. The residue in acetone was slowly added to petroleum (bp.40°-60°).

The precipitate was collected and dried affording3-acetoxymethyl-7β-[2-hydroxyimino-2-(pyrid-4-yl)acetamido]ceph-3-em-4-carboxylicacid trifluoroacetic acid salt (syn-isomer)

(0.66 g., 99%), [α]_(D) +47.5° (c 0.84, DMSO), λ_(max). (pH 6 buffer)248.5 nm (ε17,000), λ_(max). (Nujol) 3250 (NH), 1772 (β-lactam), 1720(OAc), 1660 (CF₃ CO₂ ⁻), 1660 and 1530 cm.⁻¹ (CONH), τ (d₆ -DMSO) 0.16(d, J 8 Hz; NH), 1.14 and 2.20 (multiplets, aromatic protons), 4.06 (q,J 5 and 8 Hz; C-7H), 4.71 (d, J 5 Hz; C-6H), 4.92 and 5.24 (2d, J 13 Hz;C-CH₂), 6.25 and 6.61 (2d, J 18 Hz; C-2 CH₂), 7.93 (s; OCOCH₃).

EXAMPLE A Dry Powder for Injection

The sterile sodium3-acetoxymethyl-7β-[2-hydroxyimino(thien-2-yl)acetamido]ceph-3-em-4-carboxylate(syn-isomer) powder was filled into glass vials, the claimed fillweights being 500 mg. and 1.0 g antibiotic. Filling was carried outaseptically under a blanket of nitrogen. The vials were closed usingrubber discs held in position by aluminium sealing rings, therebypreventing gaseous exchange or ingress of micro-organisms. The productwas intended for reconstitution with water for injections or othersuitable sterile vehicle shortly before administration.

EXAMPLE B Intramammary Infusion for Cattle

    ______________________________________                                        Percentage composition (w/w)                                                  ______________________________________                                        Sodium 3-acetoxymethyl-7β-[2-hydroxyimino-                               (thien-2-yl)acetamido]-ceph-3-em-4-                                           carboxylate (syn-isomer)  10.00                                               Vehicle to:               100.00                                              Vehicle Tween 60          3.00                                                 White Beeswax            6.00                                                 Arachis Oil              91.00                                               ______________________________________                                    

The last three ingredients were heated together at 150° C. for one hourand then cooled to room temperature with stirring. The sterileantibiotic powder was added aseptically to this vehicle and the productrefined with a high speed stirrer. The preparation was filledaseptically into sterile collapsible aluminium tubes with a fill weightof 3.0 g., each tube containing 300 mg. cephalosporin derivative.

We claim:
 1. A cephalosporin antibiotic of the formula ##STR34## whereinR is phenyl, naphthyl, thienyl, furyl, pyridyl, or phenyl substituted bychloro;R^(a) is H or ##STR35## wherein R^(c) is C₁₋₄ alkyl, C₁₋₄chloroalkyl, C₁₋₄ alkoxy, phenyl, nitrophenyl, C₁₋₄ alkylamino or C₁₋₄chloroalkylamino; and R⁹ is(a) C_(n) H_(2n+1) where n is an integer from1-7; (b) C_(n) H_(2n-1) where n is an integer from 2-7; (c) R^(v) whereR^(v) is selected from the group consisting of phenyl, hydroxyphenyl,chlorophenyl, fluorophenyl, tolyl, nitrophenyl, aminophenyl,methoxyphenyl, methylthiophenyl, thien-2-yl, thien-3-yl, pyridyl,cyclohexyl, cyclopentyl, sydnone, naphthyl or 2-ethoxynaphthyl; or (d)R^(v) (CH₂)_(m) where R^(v) has the meaning defined above under (c) andm is an integer from 1-4; or a physiologically acceptable salt thereof,said cephalosporin antibiotic being in the form of a syn-isomer free ofthe corresponding anti-isomer to the extent of at least 75% based on thetotal weight of said antibiotic.
 2. The compound of claim 1 which is3-acetoxymethyl-7β-[2-hydroxyimino-2-phenylacetamido]ceph-3-em-4-carboxylicacid (syn-isomer).
 3. The compound of claim 1 which is sodium3-acetoxymethyl-7β-[2-hydroxyimino-2-phenylacetamido]ceph-3-em-4-carboxylate(syn-isomer).
 4. The compound of claim 1 which is3-acetoxymethyl-7β-[2-hydroxyimino-2-(thien-2-yl)acetamido]ceph-3-em-4-carboxylicacid (syn-isomer).
 5. The compound of claim 1 which is sodium3-acetoxymethyl-7β-[2-hydroxyimino-2-(thien-2-yl)acetamido]ceph-3-em-4-carboxylate(syn-isomer).
 6. The compound of claim 1 which is7β-(2-hydroxyimino-2-phenylacetamido)-3-pivaloyloxymethylceph-3-em-4-carboxylicacid (syn-isomer).
 7. The compound of claim 1 which is3-benzoyloxymethyl-7β-(2-hydroxyimino-2-phenylacetamido)ceph-3-em-4-carboxylicacid (syn-isomer).
 8. The compound of claim 1 which is3-crotonoyloxymethyl-7β-(2-hydroxyimino-2-phenylacetamido)ceph-3-em-4-carboxylicacid (syn-isomer).
 9. The compound of claim 1 which is7β-(2-hydroxyimino-2-phenylacetamido)-3-isobutyryloxymethylceph-3-em-4-carboxylicacid (syn-isomer).
 10. The compound of claim 1 which is3-acetoxymethyl-7β-[2-(4-chlorophenyl)-2-hydroxyiminoacetamido]ceph-3-em-4-carboxylicacid (syn-isomer).
 11. The compound of claim 1 which is3-acetoxymethyl-7β-(2-hydroxyimino-2-naphth-1'-ylacetamido)ceph-3-em-4-carboxylicacid (syn-isomer).
 12. The compound of claim 1 which is7β-(2-acetoxyimino-2-phenylacetamido)-3-acetoxymethylceph-3-em-4-carboxylicacid (syn-isomer).
 13. The compound of claim 1 which is3-acetoxymethyl-7β-(2-chloroacetoxyimino-2-phenylacetamido)ceph-3-em-4-carboxylicacid (syn-isomer).
 14. The compound of claim 1 which is3-acetoxymethyl-7β-(2-ethoxycarbonyloxyimino-2-phenylacetamido)ceph-3-em-4-carboxylicacid (syn-isomer).
 15. The compound of claim 1 which is3-acetoxymethyl-7β-(2-benzoyloxyimino-2-phenyl-acetamido)ceph-3-em-4-carboxylicacid (syn-isomer).
 16. The compound of claim 1 which is3-acetoxymethyl-7β-[2-(4-nitrobenzoyloxyimino)-2-phenylacetamido]ceph-3-em-4-carboxylicacid (syn-isomer).
 17. The compound of claim 1 which is3-acetoxymethyl-7β-(2-ethylcarbamoyloxyimino-2-phenylacetamido)ceph-3-em-4-carboxylicacid (syn-isomer).
 18. The compound of claim 1 which is3-acetoxymethyl-7β-[2-(2-chloroethyl)carbamoyloxyimino-2-phenylacetamido]ceph-3-em-4-carboxylicacid (syn-isomer).
 19. The compound of claim 1 which is3-acetoxymethyl-7β-[2-hydroxyimino-2-(thien-3-yl)acetamido]ceph-3-em-4-carboxylicacid (syn-isomer).
 20. The compound of claim 1 which is3-acetoxymethyl-7β-[2-hydroxyimino-2-(fur-2-yl)acetamido]ceph-3-em-4-carboxylicacid (syn-isomer).
 21. The compound of claim 1 which is3-acetoxymethyl-7β-[2-ethoxycarbonyloxyimino-2-(thien-2-yl)-acetamido]ceph-3-em-4-carboxylicacid (syn-isomer).
 22. The compound of claim 1 which is7β-[2-acetoxyimino-2-(thien-2-yl)acetamido]-3-acetoxymethylceph-3-em-4-carboxylicacid (syn-isomer).
 23. The compound of claim 1 which is3-acetoxymethyl-7β-[2-chloroethylcarbamoyloxyimino)-2-(thien-2-yl)acetamido]ceph-3-em-4-carboxylicacid (syn-isomer).
 24. The compound of claim 1 which is3-acetoxymethyl-7β-[2-hydroxyimino-2-(pyrid-4-yl)acetamido]-ceph-3-em-4-carboxylicacid (syn-isomer).
 25. The compound of claim 1 which is3-crotonoyloxymethyl-7β-[2-hydroxyimino-2-(thien-2-yl)acetamido]ceph-3-em-4-carboxylicacid (syn-isomer).